Simultaneous air cooling of multiple elements of a hybrid power plant

Abstract

The aerospace hybrid powertrain system includes an engine, a power shaft, and an electric machine having the power shaft therein or passing through the power shaft. The aerospace hybrid powertrain system further includes a fan, impeller, or blower connected to the power shaft and configured to direct air toward at least one of the engine or electric machine components. The fan, impeller, or blower may be further configured to direct air toward a cooling element, such as a heat exchanger or finned heat sink, arranged to cool at least one of the piston combustion engine or electric machine components.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED PATENT APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 280,568, filed November 17, 2021, and U.S. Provisional Patent Application No. 63 / 163,165, filed March 19, 2021, the entire contents of each of which are incorporated herein by reference in their entirety. [Background technology]

[0002] There are various types of aircraft that are propelled using different kinds of propulsion mechanisms, such as propellers, turbine or jet engines, rockets, or ramjets. The different types of propulsion mechanisms may be powered in different ways. For example, some propulsion mechanisms, such as propellers, may be powered by an internal combustion engine or an electric motor. As such, the combination of the propulsion mechanisms and the methods of powering those propulsion mechanisms are often specially designed for a particular aircraft, such that the propulsion mechanisms and the methods of powering those propulsion mechanisms meet the specifications necessary to properly and safely propel the aircraft. Summary of the Invention

[0003] In one embodiment, the aerospace hybrid powertrain system includes an engine, a power shaft, and an electric machine having the power shaft therein or passing through the power shaft. The aerospace hybrid powertrain system further includes a fan, impeller, or blower connected to the power shaft, the fan, impeller, or blower may be configured to direct air toward at least one of the engine or electric machine components. The fan, impeller, or blower may be further configured to direct air toward a cooling element, such as a heat exchanger or finned heat sink, positioned to cool at least one of the engine or electric machine components.

[0004] In one embodiment, the aerospace hybrid powertrain system includes an engine, a power shaft, and an electric machine having the power shaft therein or passing through the power shaft. The electric machine is configured to output electrical power to a direct current (DC) bus, and the electrical power on the DC bus is configured to be used to propel the aircraft. The aerospace hybrid powertrain system further includes a fan, impeller, or blower connected to the fan, impeller, or blower shaft. The fan, impeller, or blower is configured to direct air toward at least one component of the engine, the electric machine, or a cooling element including at least one of a heat exchanger or a finned heat sink configured to cool at least one component of the engine or the electric machine. The fan, impeller, or blower shaft is indirectly supplied with mechanical power from the power shaft.

[0005] In one embodiment, a method for controlling cooling of an aerospace hybrid powertrain system includes a processor of a computing device receiving data indicative of at least one of a temperature associated with a component of the aerospace hybrid powertrain system or an ambient or environmental temperature. The method further includes the processor determining a desired level of cooling for the component based on the temperature associated with the component of the aerospace hybrid powertrain system or the ambient or environmental temperature. The method further includes the processor outputting a control signal configured to change a state of an airflow control device to regulate airflow to the component of the aerospace hybrid powertrain system based on the determination of the desired level of cooling. [Brief description of the drawings]

[0006] [Figure 1A] FIG. 1 illustrates an example of a flexible architecture for an aerospace hybrid system in accordance with an illustrative embodiment. [Figure 1B] FIG. 1 illustrates an additional example of a flexible architecture for an aerospace hybrid system in accordance with an illustrative embodiment. [Figure 2A] FIG. 1 is a block diagram illustrating a first aircraft control system for use with the flexible architecture of the aerospace hybrid system in accordance with an illustrative embodiment. [Figure 2B] FIG. 1 is a block diagram illustrating a second aircraft control system for use with the flexible architecture of the aerospace hybrid system in accordance with an illustrative embodiment. [Diagram 3] FIG. 1 illustrates a first example of an aircraft that can use the flexible architecture of an aerospace hybrid system in accordance with an illustrative embodiment. [Figure 4] FIG. 1 illustrates a second example of an aircraft that can use the flexible architecture of an aerospace hybrid system in accordance with an illustrative embodiment. [Diagram 5] FIG. 10 illustrates a third example of an aircraft that may use the flexible architecture of an aerospace hybrid system in accordance with an illustrative embodiment. [Figure 6] 1 is a flowchart illustrating a first exemplary method for using a flexible architecture of an aerospace hybrid system during different flight phases of an aircraft equipped with a main propulsion propeller, in accordance with an exemplary embodiment. [Figure 7] 1 is a flowchart illustrating a second exemplary method for using a flexible architecture of an aerospace hybrid system during different flight phases of an aircraft equipped with a main propulsion propeller, in accordance with an exemplary embodiment. [Figure 8A] FIG. 1 illustrates an example of a flexible architecture for an aerospace hybrid system having a flywheel in accordance with an illustrative embodiment. [Figure 8B] FIG. 1 illustrates an example of a flexible architecture for an aerospace hybrid system having a flywheel and a spring coupler in accordance with an illustrative embodiment. [Figure 9] 1 is a schematic diagram of an example cooling system for a hybrid power plant according to an exemplary embodiment. [Figure 10]FIG. 1 illustrates an example of a hybrid power plant with a cooling system according to an exemplary embodiment. [Figure 11] 11 is a cross-sectional view of an example hybrid power plant with the cooling system of FIG. 10 according to an exemplary embodiment. [Figure 12] 11 is a partial cross-sectional perspective view of an example hybrid power plant including the cooling system of FIG. 10 according to an exemplary embodiment. [Figure 13] 2 is a schematic diagram of a second example cooling system for a hybrid power plant in accordance with an illustrative embodiment. [Figure 14] 1 is a schematic diagram of a third example cooling system for a hybrid power plant in accordance with an illustrative embodiment. [Figure 15] 11 is a schematic diagram of a fourth example cooling system for a hybrid power plant in accordance with an illustrative embodiment. [Figure 16] 13 is a schematic diagram of a fifth example cooling system for a hybrid power plant in accordance with an illustrative embodiment. [Figure 17] 1 is a top view of an example hybrid power plant with a cooling system according to an exemplary embodiment; [Figure 18] 18 is a cross-sectional view taken along line AA of FIG. 17, illustrating an example of the hybrid power plant of FIG. 17, according to an exemplary embodiment. [Figure 19] 18 along line BB of FIG. 18, illustrating an example of the hybrid power plant of FIG. 17, according to an exemplary embodiment. [Figure 20] 18 is an alternative view of the example hybrid power plant of FIG. 17 showing engine cooling fins details in accordance with an exemplary embodiment. [Figure 21] 18 is a side view of the example hybrid power plant of FIG. 17 with a cooling system according to an exemplary embodiment. [Figure 22] 4 is a flowchart illustrating an example method for controlling a cooling system, according to an example embodiment. [Figure 23] FIG. 1 illustrates a perspective view of an example flexible architecture for an aerospace hybrid system in accordance with an illustrative embodiment. [Figure 24] FIG. 24 is a top view of the example flexible architecture of FIG. 23 in accordance with an exemplary embodiment. [Diagram 25] FIG. 24 is a side view of the example flexible architecture of FIG. 23 in accordance with an exemplary embodiment. [Figure 26] FIG. 1 is a perspective view of another example of a flexible architecture for an aerospace hybrid system in accordance with an illustrative embodiment. [Figure 27] FIG. 1 illustrates an example of downstream and upstream components for propelling an aircraft in accordance with an illustrative embodiment. [Figure 28A] FIG. 2 illustrates a portion of a cooling system including a cross section of the ductwork of the cooling system according to an exemplary embodiment. [Figure 28B] FIG. 2 illustrates a portion of a cooling system including a cross section of the ductwork of the cooling system according to an exemplary embodiment. [Figure 28C] FIG. 2 illustrates a portion of a cooling system including a cross section of the ductwork of the cooling system according to an exemplary embodiment. [Figure 29A] 1 illustrates an additional portion of a cooling system, including additional details of the ductwork of the cooling system, according to an exemplary embodiment. [Figure 29B] 1 illustrates an additional portion of a cooling system, including additional details of the ductwork of the cooling system, according to an exemplary embodiment. [Diagram 30] 1 is a diagram of an example computing environment in accordance with an illustrative embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] Aircraft typically have custom-designed propulsion mechanisms and methods for powering those propulsion mechanisms. In this way, the propulsion mechanisms and the power provided to those propulsion mechanisms can be optimized to provide the amount of propulsion required for a particular type and size of aircraft while minimizing the weight of components within the aircraft. In other words, the propulsion mechanisms and the power of those propulsion mechanisms are often optimized for a particular type and size of aircraft, so that components of one aircraft cannot easily be used with different types of aircraft drive architectures, such as direct drive aircraft, parallel drive aircraft, and serial drive aircraft.

[0008] Various embodiments of flexible architectures and optimized components thereof for aerospace hybrid systems are described herein. A hybrid system may be or include a system in which fuel is combusted in a piston, turbine, rotary, or other engine and the output of the engine is operatively connected to a generator to output electrical power. The embodiments described herein may include a flexible system capable of powering many different types of aircraft and propulsion mechanisms. Such a system may advantageously reduce the complexity of designing different types of aircraft, reduce the manufacturing costs of such systems as less customization allows for economies of scale in mass production of the systems, and ultimately reduce the complexity of aircraft using the systems described herein.

[0009] The flexible architecture described herein may further be used to power propulsion mechanisms in different ways within the same aircraft or different aircraft. For example, a flexible architecture for powering propulsion mechanisms may be capable of operating in multiple different modes to power different types of propulsion mechanisms. A first aircraft may utilize one, some, or all of the multiple different modes in which the flexible architecture can operate. A second aircraft may utilize one, some, or all of the multiple different modes, and the mode utilized by the second aircraft may be different from the mode utilized by the first aircraft.

[0010] Thus, different aircraft may utilize different modes of powering the propulsion mechanisms provided by the flexible architecture described herein. Although the use of the flexible architecture may be customized in this manner, the physical hardware of the flexible architecture may be adapted for use by different aircraft with minimal or no changes to the physical components of the flexible architecture described herein. Instead, the use of different modes in different aircraft may be achieved primarily based on how the components of the flexible architecture are controlled using a processor or controller. Thus, computer readable instructions may be stored in a memory operatively coupled to a processor or controller, such that when the instructions are executed by the processor or controller, a computing device including the processor or controller may control the various components of the flexible architecture described herein to utilize any possible modes of use desired for a particular implementation, aircraft, flight phase, etc.

[0011] Power generation and propulsion systems for aircraft may also utilize various cooling systems to ensure that various components of the aircraft are kept at safe temperatures for operation, as well as to ensure that the components remain within temperature ranges that they can operate more efficiently. Further, described herein are advantageous cooling systems that utilize various aspects of the hybrid architecture described herein to efficiently cool components of a flexible architecture for powering the propulsion mechanisms of an aircraft.

[0012] An aircraft having hardware for providing different modes of power to the propulsion mechanisms may have various components for which it is desirable to provide cooling. Thus, a single cooling system that efficiently moves air to the various components that enable the different power modes may reduce the weight of the aircraft as well as the power consumption of the cooling system. Figures 1-8 and the following accompanying description relate specifically to an example flexible architecture for powering the propulsion system of an aircraft. Figures 9-21 and the following accompanying description relate to various embodiments of a cooling system for the example flexible architecture.

[0013] 1A illustrates an example of an aerospace hybrid system flexible architecture 101 in accordance with an illustrative embodiment. As discussed herein, the flexible architecture 100 can be efficiently used in a wide range of applications with a single hybrid generator system that can be adapted in multiple ways (e.g., used in different modes) depending on the aircraft requirements and flight phase.

[0014] The flexible architecture 100 of FIG. 1A is a hybrid generator including an engine 105, a clutch 115, a generator / motor 121, and a power shaft 111. As described further below, the flexible architecture 100 can be used to achieve a variety of different modes, as needed, depending on the installation requirements of a particular aircraft or a particular flight phase. The engine 105 can be a combustion engine, such as an internal combustion engine. More specifically, the engine 105 can be one of a piston internal combustion engine, a rotary engine, or a turbine engine. Such engines can use standard gasoline, jet fuel (e.g., Jet A, Jet A-1, Jet B fuel), diesel fuel, kerosene, gasoline, hydrogen, biofuel, synthetic fuel alternatives (e.g., biofuel alternatives), and the like. In various embodiments, other types of engines can be used, such as a small engine (e.g., a Rotax gasoline engine) in a drone implementation.

[0015] As discussed above, the engine 105 may be a piston, rotary, or turbine combustion engine. A piston combustion engine may advantageously rotate an output rotor or shaft at revolutions per minute (RPM) that is more desirable for direct output to power an electrical generator and / or a propulsion mechanism (e.g., a propeller) than other engines. For example, a piston combustion engine may have an output on the order of several thousand RPM. For example, the output of a piston combustion engine may be in the range of 2200-2500 RPM, which may be a desirable RPM for a propeller. In particular, the propeller may be designed to have a size that results in a desired tip speed of the propeller based on the RPM output of the piston combustion engine (e.g., 2200-2500 RPM). Other types of engines, such as turbine engines, may output rotational power on the order of tens of thousands of RPM, much higher than a piston combustion engine. For example, turbojet, turboprop, and / or turbofan engines may provide shaft output at similar RPMs, but at a higher RPM than a piston engine, e.g., anywhere from 5000-30,000 RPM. In another example, a turbine engine with a gearbox, such as a turboshaft engine, may operate at a similar RPM or other desired RPM range as a piston engine due to the flexibility of the gearbox to incrementally increase or decrease the engine's output RPM. Other embodiments may drive a motor / generator at the higher RPM of a turbine or rotary engine to benefit efficiency, power output, or other important factors. In some embodiments, a gearbox may be added between the output of the high RPM engine and other components of FIG. 1A to lower the output RPM of the engine 105. However, adding a gearbox may also increase the weight of the system. Piston combustion engines may generate less noise compared to turbine engines. Turbine engines may be louder and / or generate noises at different (e.g., higher) frequencies than piston combustion engines, and such noises from turbine engines as perceived by humans are more annoying to listeners than noises generated by piston combustion engines.Quieter engines may be more valuable in urban or densely populated environments where reduced noise is desired. Piston engines may also be more fuel efficient than turbine engines, so if fuel efficiency is desired in a given embodiment, that efficiency may be considered when determining which type of engine to use.

[0016] The engine 105 can output rotational power to the clutch 115, which can be controlled to engage or disengage the power shaft 111. In other words, the power shaft 111 can be engaged with the rotational output of the engine 105 by the clutch 115, whereby torque / rotational force can be transferred between the output of the engine 105 and the power shaft 111. When the clutch 115 is disengaged from the output of the engine 105 and the power shaft 111, the power shaft 111 can rotate independently of the output of the engine 105. The clutch 115 can be physically located between the engine 105 and the generator / motor 121, and can even contact the opposite side of the engine 105 and the generator / motor 121 to reduce the overall footprint of the flexible architecture. In FIG. 1A, the clutch 115 is further described herein and shown in other figures. However, in various embodiments, any mechanism capable of releasably decoupling the engine 105 and the power shaft 111 can be used in addition to or in place of the clutch. For example, the decoupling can be based on absolute revolutions per minute (RPM) between the output of the engine 105 and the power shaft 111 or on the relative RPM, such as in an overrunning clutch. In various embodiments, a clutch may not be used, as described herein (e.g., with respect to FIG. 8B). Instead, a solid shaft may be used, and such embodiments may use a spring coupler, a flywheel, and / or a torque converter (e.g., a fluid torque converter) to transfer power from the output of the engine 105 to the power shaft 111.

[0017] The generator / motor 121 may also be engaged with the power shaft 111 or disengaged from the power shaft 111. In other words, the generator / motor 121 may be controlled to be switched off so that the rotation of the power shaft 111 does not cause the generator / motor 121 to generate power. Similarly, the generator / motor 121 may be controlled to be switched on so that the rotation of the power shaft causes the generator / motor 121 to generate power. The generator / motor 121 is referred to as a generator / motor because it can function as both a generator and a motor. In various embodiments, the generator / motor 121 may be referred to as an electric machine, which may be a generator, an electric motor, or both.

[0018] The flexible architecture further includes a power input / output (I / O) 125 connected to the generator / motor 121. As described further herein, the generator / motor 121 may generate power based on the rotation of the power shaft 111 that is output via the power I / O 125, or may receive power via the power I / O 125 that may be used to drive the power shaft 111. The wiring of the power I / O 125 may include multiple wires. In various embodiments, the wiring for inputting power to the generator / motor 121 may be the same as the wiring used to output power from the generator / motor 121. In various other embodiments, a first wiring may be used for inputting power and a different second wiring may be used for outputting power (using different wiring for input and output). In various embodiments, the generator / motor 121 may also have wiring that is used to control the generator / motor 121 and is connected to relay sensor or other data regarding the operation of the generator / motor 121 to a controller or the like.

[0019] The generator / motor 121 can also function as a driver for the power shaft 111. Upon receiving power via the power I / O 125 from a battery or some other form of electrical energy storage elsewhere in the system, the generator / motor 121 can provide a rotational force to drive the power shaft 111. This can occur as long as the generator / motor 121 is controlled to be switched on so that it is engaged with the power shaft 111. If the generator / motor 121 is controlled to be switched off so that it is not engaged with the power shaft 111, the power shaft 111 may no longer be rotated by the generator / motor 121.

[0020] The power output from the power I / O 125 may be used to drive electric motors for electric propulsion (e.g., propellers). The power output from the power I / O 125 may also be used to power and / or charge other devices on the aircraft or aerospace vehicle. For example, the power output from the power I / O 125 may be used to charge one or more batteries. The power output from the power I / O 125 may also be used to power other devices or accessories on the aircraft or aerospace vehicle. Because the power I / O 125 also has an input, the power shaft 111 may be driven by any power received via the power I / O 125, such as power from one or more batteries. The power generated by the generator / motor 121 may be alternating current (AC) power. The AC power may be converted to direct current (DC) power by power electronics (e.g., a rectifier or inverter) and output to a DC bus. This DC bus may be connected to a battery and / or an electric propulsion. In this manner, the electric propulsion may be powered via the DC bus. In various embodiments, the motors of the electric propulsion mechanisms may use AC power, and therefore the DC power from the DC bus may be converted from DC power to AC power before being used by the electric propulsion mechanisms (e.g., an inverter).

[0021] Any rotation of the power shaft 111 itself may also be used to drive one or more propulsion mechanisms, whether driven by the engine 105 or the generator / motor 121. For example, the rotation of the power shaft 111 may be used to directly drive a propeller or may be used to power an electric motor that drives the propulsion mechanism. The rotation of the power shaft 111 may also drive a gearbox that is operatively connected to another component, such as one or more propellers, one or more rotors, or other rotating devices for various applications on the aircraft.

[0022] The accessory pad 130 may also be coupled to the engine 105 and may include a low voltage direct current (DC) generator for power separate from the generator / motor 121 and power I / O 125, which may be configured for high voltage and high power I / O. In some embodiments, the generator / motor 121 may have two different windings and the power I / O 125 may have two different outputs (e.g., high voltage and low voltage). An accessory power source may be associated with one of the outputs of the power I / O 125 in addition to or instead of the output of the accessory pad 130. The accessory pad 130 may be used to power devices or accessories on the aircraft or aerospace vehicle that do not require the high voltage or current output that may be output by the generator / motor 121 at the power I / O 125. The voltage (HV) of the aircraft may be, for example, 400 volts (V), 800V, 1200V, or 3000V, but may be anywhere between 50V and 3000V in various embodiments. The low voltage (LV) of the aircraft may be 12V, 14V, 28V, or other voltage less than 50V.

[0023] FIG IB illustrates an additional example of a flexible architecture 150 for an aerospace hybrid system in accordance with an illustrative embodiment. In particular, the flexible architecture 150 of FIG IB includes several components that may be the same or similar to those described above with respect to FIG 1A, where the flexible architecture 150 includes an engine 155, a clutch 175, a power shaft 180, and / or a generator / motor 185. The flexible architecture 150 further illustrates an output of the engine 155 in the form of a crankshaft 160, which is rigidly connected to an output flange 165. The output flange 165 is rigidly connected to one side of the clutch 175 using bolts 170.

[0024] The clutch 175 may be configured to engage the power shaft 180 to transfer rotational motion from the crankshaft 160 and the output flange 165 to the power shaft 180. The clutch 175 may further be configured to disengage from the power shaft 180, thereby allowing the power shaft 180 to rotate independently relative to the crankshaft 160 and the output flange 165. Additionally, FIG. 1B illustrates how all of the rotatable components of the flexible architecture 150 may be aligned along a single axis 190. The rotatable components of FIG. 1A may similarly be aligned along a single axis as shown in FIG. 1B. Additionally, the power shaft 180 may be a splined shaft that fits into the inner diameter openings of the clutch 175 and the generator / motor 185. Other features other than splines, such as tapers, may also be used. In either case, the generator / motor 185 and / or the clutch 175 may be configured to match and connect to the splines, tapers, or other features on the power shaft 180 so that the components can properly engage with one another.

[0025] In various embodiments, the clutch 175 may be a different type of clutch or other mechanism capable of decoupling the power shaft 180 from the output of the engine 155. For example, the clutch 175 may be a plate-type clutch and may be a dry or wet clutch. Such a plate-type clutch may be engaged / disengaged or otherwise controlled mechanically, hydraulically, and / or electrically (e.g., by the controllers 205, 220, and / or 280 of FIGS. 2A and 2B). A plate-type clutch may have a variety of numbers of plates, such as three, five, or ten plates. In various embodiments, the clutch 175 or other clutches described herein may be a one-way clutch, an overrunning clutch, or a sprag clutch. A one-way clutch or a sprag clutch may be configured to disengage the engine output from the power shaft while the electric machine rotates the power shaft faster than the engine output. In other words, when the engine 155 is outputting less power to the power shaft 180 than the generator / motor 185, the clutch 175 can automatically mechanically disengage the output of the engine 155 from the power shaft 180, e.g., without any electrical control input being used to accomplish that disengagement. When the engine 155 has a higher RPM or outputs more power than the generator / motor 185, a one-way or sprag clutch is engaged so that power is added from the output of the engine 155 to the power shaft 180. Another type of clutch that can be used is a centrifugal clutch, where as the RPM increases, the weight of the plates of the clutch gradually activates one or more levers, compressing the plates of the centrifugal clutch and engaging the plates to connect, e.g., the output of the engine 155 and the power shaft 180.

[0026] Advantageously, the generator / motor 121 and / or the generator / motor 185 of FIG. 1A may be used as a starter for the engine 105 or the engine 155, respectively. In other words, the generator / motor 185 may be used to rotate the crankshaft 160 while the clutch 175 is engaged to start the engine 155. Such a system may be advantageous, for example, where the generator / motor 185 may be powered by a battery or other power source. Thus, the engine 155 may be a piston, rotary, or turbine combustion engine as described herein, without the need for a separate starter component, reducing the weight and complexity of the flexible architecture described herein.

[0027] FIG. 2A illustrates a block diagram depicting an aircraft control system 200 used with a flexible architecture 201 for an aerospace hybrid system, according to an exemplary embodiment. The aircraft control system 200 may be used to realize one or more of the various modes discussed below, in which the flexible architecture described herein may be used, for example. The flexible architecture 201 may be the same as, similar to, or have some or all of the components of the flexible architectures 101 and / or 150 of FIG. 1A and / or FIG. 1B. The aircraft control system 200 may include one or more processors or controllers 205 (hereinafter referred to as controller 205), memory 210, an aircraft main controller 220, an engine 230, a generator / motor 235, a clutch 240, a power I / O 245, an accessory pad 250, and one or more sensors 260. The connections in FIG. 2A illustrate control signal related connections between the components of the aircraft control system 200. Other connections not shown in FIG. 2A may exist between different aspects of the aircraft and / or aircraft control system 200 to provide power, such as high voltage (HV) or low voltage (LV) power for the aircraft.

[0028] The memory 210 may be a computer-readable medium configured to store instructions. Such instructions may be computer-executable code executed by the controller 205 to implement various methods and systems described herein, including various modes and combinations of modes using the flexible architecture herein. The computer code may be written such that various methods of implementing different modes of the flexible architecture herein are automatically implemented based on various inputs, for example, indicative of a particular flight phase (e.g., landing, takeoff, cruise, etc.). In various embodiments, the computer code may be written to implement various modes herein based on inputs from a user or pilot of the aircraft or aerospace vehicle, or may be implemented based on a combination of user inputs and automatic implementations based on non-human inputs (e.g., from sensors on or off the aircraft, based on a planned flight plan, etc.). The controller 205 may be powered by a power source on the aircraft or aerospace vehicle, such as the accessory pad 130, one or more batteries, an output of the power I / O 125, a power bus of the aircraft powered by any power source, and / or any other available power source.

[0029] The controller 205 may also communicate with each of the engine 230, the generator / motor 235, the clutch 240, the power I / O 245, the accessory pads 250, and / or the sensors 260. In this manner, the components of the flexible architecture may be controlled to achieve the various modes described herein. In various embodiments, the engine 230, the generator / motor 235, the clutch 240, the power I / O 245, and the accessory pads 250 may be similar to or similarly named components shown in and described above with respect to FIG. 1A. The power I / O 245 may also include pre-charge electronics to protect the electrical components of the flexible architecture, including, for example, a direct current (DC) bus, from excessive inrush current during startup as described herein. For example, if a high voltage (HV) bus is 400V and a new component is connected to the 0V HV bus, the instantaneous inrush current may be very large and may cause damage to the HV bus and / or the component. As a result, the pre-charge electronics can slowly ramp up the voltage of the components before fully connecting to the HV bus or other power source. In various embodiments, the HV bus can be a DC bus or an AC bus, or there can be multiple buses that are either DC or AC buses. If an AC bus is used, AC power can be output directly from the motor / generator to the AC bus. If a DC bus is used, an inverter can be used to convert the AC power from the motor / generator to DC power and output to the DC bus.

[0030] Sensors 260 may include various sensors for monitoring different components of flexible architecture 201. Such sensors may include temperature sensors, tachometers, fluid pressure sensors, voltage sensors, current sensors, status sensors, or other types of sensors, for example, to determine the current state of clutch 250. For example, voltage and / or current sensors may be used to indicate the function and settings of the motor / generator, to inform the clutch of the selected state, or to adjust other components of the system. Status sensors may also indicate the particular mode in which the flexible architecture is being used, and the system may receive input (e.g., from the pilot, from an automatic flight control) to change the system to a different state or mode for a particular upcoming flight phase. Other sensors may include a pitot tube to measure the airspeed of the aircraft, an altimeter to measure the altitude of the aircraft, and / or a global positioning system (GPS) or similar geographic location sensor to determine a position relative to the ground and / or known / mapped structures.

[0031] The components within the dashed lines of flexible architecture 201 in FIG. 2A may be associated with the flexible architecture described herein, while aircraft main controller 220 may be associated with a broader aircraft system. In other words, aircraft main controller 220 may control aspects of the aircraft other than flexible architecture 201, while controller 205 may control aspects of the aircraft related to flexible architecture 201. Aircraft main controller 220 and controller 205 may communicate with each other to coordinate the powering of various propulsion mechanisms of the aircraft. For example, aircraft main controller 220 may send signals to control device 205 requesting a particular power output level for one or more particular propulsion mechanisms. Controller 205 may receive such control signals and determine how to coordinate flexible architecture 201 (e.g., which mode to enter, how to control elements of flexible architecture 201) to output the desired power level based on the control signals from aircraft main controller 220. In various embodiments, aircraft main controller 220 may send signals related to the control of particular aspects of flexible architecture 201. In other words, in addition to or instead of transmitting a desired power output signal to controller 205, controller 205 can function as a repeater to retransmit control signals from aircraft main controller 220 to the components of flexible architecture 201, and controller 205 determines from the control signals how to control the individual components of flexible architecture 201.

[0032] In various embodiments, aircraft main controller 220 may also transmit control signals related to future desired power output, future flight phases, flight plan information, and the like. In this manner, controller 205 may receive information regarding the anticipated power requirements of the aircraft and use it to determine how to control aspects of flexible architecture 201, both currently and in the future. For example, flight plan information may be used to determine when to use battery power, when to charge batteries, and the like. In another example, when a large power demand is anticipated, controller 205 may ensure that engines 230 are operating at a desired RPM and begin to deliver a desired level of power by controlling engine output depending on how much fuel the engine uses (e.g., if a diesel piston, diesel rotary, or turbine engine is used) and / or how much air the engine uses (e.g., if a gasoline piston engine is used).

[0033] In various embodiments, the controller 205 may also communicate with one or more batteries to monitor their charge levels, control when the batteries are charged or discharged, control when the batteries are used to power the generators / motors 235, and control when the batteries are used to directly power other aspects of the aircraft. However, in other embodiments, the aircraft main controller 220 may communicate with the aircraft batteries and / or relay information regarding the batteries and their control to the controller 205. Similarly, if the aircraft batteries are controlled using the aircraft main controller 220 rather than the controller 205, the controller 205 may send control signals related to the batteries to the aircraft main controller so that the batteries may be controlled as needed or desired for the function of the flexible architecture 201. Control of the batteries may be achieved through communication with the battery controller. Control of the batteries may additionally or alternatively be achieved by monitoring the voltage of the bus to which the batteries are connected as well as the current flowing into and / or out of the battery energy storage system (e.g., the bank of batteries and / or the battery controller). For example, a control system (e.g., controller / processor) can make advantageous decisions regarding engine control, motor / generator control, and / or other features necessary for safe, reliable, and energy-efficient operation based on the measured bus voltage and / or current flowing into and / or out of the battery.

[0034] In various embodiments, the power I / O 245 may include two different outputs (e.g., a high voltage (HV) output and a low voltage (LV) output) associated with two different windings of the generator / motor 235. Thus, two different voltages (e.g., HV and LV) may be output and controlled by the controller 205 and / or the aircraft main controller 220. The power I / O 245 may additionally or alternatively have voltage conversion components (e.g., DC / DC converters) to enable it to output two or more different voltages. In such an embodiment, the two different outputs may be achieved without using two separate windings. The two different outputs may be output to different power buses of the aircraft, such as, for example, an HV bus and an LV bus. The two outputs of the power I / O 245 may also be independently controlled by the controller 205. Thus, the outputs may be turned off (e.g., by turning off the field current of the motor / generator, thereby allowing the generator's power shaft and rotor to rotate or freewheel relative to the rest of the motor / generator). In various embodiments, the power shaft may not actually freewheel within the generator / motor 235. Instead, the power shaft may rotate the rotor of the motor / generator 235 while the stator remains stationary, but the controller 205 may be used to control the output such that little or no power is actually output by the motor / generator 235. In various embodiments, the controller 205 may control the motor / generator 235 to output a desired or threshold level of power from the motor / generator 235 while the remaining power is output by the power shaft (e.g., to a propulsion mechanism). For example, the controller 205 may control the motor / generator 235 to generate as electrical power between 0% and 100% of the power output by the engine to the power shaft.For example, the controller 205 may cause the motor / generator 235 to generate 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 98%, 99%, or 100% of the power from the power shaft as electrical power.

[0035] In some embodiments, the accessory pad may not be controlled by controller 205 and / or aircraft main controller 220. The accessory pad may be on when engines 230 are running to provide power to aircraft accessories.

[0036] In some embodiments, controller 205 may communicate with a wireless transceiver that may be onboard an aircraft or aerospace vehicle, thereby allowing controller 205 to communicate with other computing devices that are not hardwired to system 200. In this manner, instructions or inputs for implementing the various modes of the flexible architecture described herein may also be received wirelessly from remote computing devices. In other embodiments, system 200 may communicate only with components onboard an aircraft.

[0037] The controller 205 may further connect to one or more aspects of the cooling system 285 of the flexible architecture 201. For example, the cooling system 285 may include one or more valves or other components to limit or control how much air is directed towards the various components of the flexible architecture 201 based on which components require cooling or do not require cooling. The cooling system 285 may also include gearboxes or other components to adjust the rotational speed of the cooling system blowers or fans, thereby allowing for further control of the cooling system. Thus, the controller 205 and / or the controller 220 may control one or more aspects of the cooling system 285 to control the cooling of the various components of the flexible architecture 201. The cooling system 285 may be or include various components of the cooling systems described herein, including those with respect to any of FIGS. 9-21. FIG. 22 further includes an exemplary method of how aspects of the cooling system may be controlled to adjust the cooling airflow of the cooling system components (e.g., the cooling system 285).

[0038] Figure 2B illustrates a block diagram representing a second aircraft control system 275 used with the flexible architecture for an aerospace hybrid system, according to an example embodiment. In the example of Figure 2B, system 275 does not have a separate aircraft main controller as in Figure 2A. Instead, the entire aircraft has the flexible architecture and a single main controller 280 that controls all aspects of the aircraft (including, for example, the aircraft's propulsion mechanism 255).

[0039] The controller 280 may communicate with and control one or more propulsion mechanisms 255 on the aircraft. The controller 280 may also communicate with one or more sensors 270 on the aircraft or aerospace vehicle, which may be aircraft sensors and flexible architecture sensors. In particular, the sensors 260 may be embedded in any of the components of Figures 1A and / or 1B described above, and thus may be used to inform how the devices of Figures 1A and / or 1B are controlled and / or how the modes described herein are implemented as described herein.

[0040] 2A or 2B, controller 205, controller 280, and / or aircraft main controller 220 may also be in communication with a cooling system configured to cool and / or heat any component of the flexible architecture, one or more batteries, or other aspects of the aircraft, such that the cooling system may also be controlled in conjunction with other systems and methods described herein.

[0041] Described below are five particular modes that may be implemented using various embodiments of the flexible architectures described herein (including, for example, the flexible architectures shown in and described with respect to Figures 1A, 1B, 2A, and 2B).

[0042] In a first mode, which may be referred to herein as a hybrid generator mode, a clutch (e.g., clutch 115 of FIG. 1A and / or clutch 175 of FIG. 1B) may be controlled to engage an engine (e.g., engine 105 of FIG. 1A and / or engine 155 of FIG. 1B) with a power shaft (e.g., power shaft 111 of FIG. 1A and / or clutch output / power shaft 180) extending between the clutch and a generator / motor (e.g., generator / motor 121 of FIG. 1A and / or generator / motor 185 of FIG. 1B), whereby the engine rotates a power shaft in the generator / motor to generate electrical power that is supplied to other systems on the aircraft, such as propulsion mechanisms / systems, via a power I / O (e.g., power I / O 125 of FIG. 1A). For example, such propulsion mechanisms / systems may be powered using an electric motor, and the electrical power output by the generator / motor in the first mode may be used to drive such propulsion mechanisms / systems. That is, in the first mode, a clutch may be used to engage the engine with a power shaft to drive a generator / motor that outputs electrical power. In various embodiments, the first mode may be achieved using a system that does not have a clutch (e.g., the system of FIG. 8B).

[0043] In a second mode, which may be referred to herein as a direct drive engine mode, a clutch (e.g., clutch 115 of FIG. 1A and / or clutch 175 of FIG. 1B) may engage an engine (e.g., engine 105 of FIG. 1A and / or engine 155 of FIG. 1B) output to a power shaft (e.g., power shaft 111 of FIG. 1A and / or clutch output / power shaft 180) that extends through a generator / motor (e.g., generator / motor 121 of FIG. 1A and / or generator / motor 185 of FIG. 1B) to provide mechanical power to a propulsion mechanism, such as a propeller of an aircraft. In such a mode, the magnetic field may be removed from the generator / motor (e.g., the generator / motor may be controlled to be off or disengaged) such that the generator / motor power shaft and rotor rotate or freewheel and thus the generator / motor power I / O (e.g., power I / O 125 of FIG. 1A) is disengaged and does not output power. That is, in the second mode, the engine can drive the power shaft to mechanically or otherwise power the propulsion mechanism, while the power shaft rotates in the generator / motor without receiving or outputting electrical power at the power I / O. As described herein, the controller can also be used to control how much electrical power the generator / motor generates and outputs at the power I / O, while allowing the remaining power on the power shaft to be output as mechanical power to the propulsion device. The propulsion device can be, for example, a rotor, a propeller, a fan, or any other means of providing thrust. Thus, for example, when the aircraft's batteries are fully charged and the aircraft's electric motors are not being used, it may be desirable to output only mechanical power to the propulsion device and not convert any of the power on the power shaft to electrical power. In other examples, it may be desirable to convert only a portion of the mechanical power from the power shaft to electrical power.For example, the controller can have the motor / generator convert a certain percentage of power from the power shaft into electrical power, or can monitor the power shaft to ensure that a minimum threshold of mechanical power is output to the propulsion mechanism (e.g., to maintain a particular airspeed or RPM of the propulsion mechanism) and then convert the remaining power from the power shaft into electrical power (e.g., to charge a battery or other energy storage device onboard the aircraft). Thus, various embodiments described herein can control the generator / motor to output a certain amount of electrical power or no / very little electrical power even while the motor / generator power shaft and rotor are rotating, which can help prevent overcharging of the aircraft's onboard batteries, reduce overall fuel consumption, etc. In various embodiments, this can be controlled by the controller to control how much electrical energy is output using the generator, or by disengaging or partially disengaging the power shaft from the rotor of the motor / generator (or vice versa). In various embodiments, the second mode can be achieved using a system without a clutch (e.g., the system of FIG. 8B).

[0044] In a third mode, which may be referred to herein as an augmented thrust mode, a clutch (e.g., clutch 115 of FIG. 1A and / or clutch 175 of FIG. 1B) may engage an engine (e.g., engine 105 of FIG. 1A and / or engine 155 of FIG. 1B) to a power shaft (e.g., power shaft 111 of FIG. 1A and / or clutch output / power shaft 180) that extends through a generator / motor (e.g., generator / motor 121 of FIG. 1A and / or generator / motor 185 of FIG. 1B), which is used as a motor drawing power via a power I / O (e.g., power I / O 125 of FIG. 1A) from an external source such as a battery pack. This provides a higher mechanical power output to the power shaft than the engine or generator / motor can provide. That is, in the third mode, both the engine and the generator / motor are used to simultaneously drive the power shaft to deliver power (electricity) to the propulsion mechanism. In various embodiments, the third mode can be achieved using a system without a clutch (eg, the system of FIG. 8B).

[0045] In a fourth mode, which may be referred to herein as a direct drive generator / motor mode, a clutch (e.g., clutch 115 of FIG. 1A and / or clutch 175 of FIG. 1B) may disengage the engine (e.g., engine 105 of FIG. 1A and / or engine 155 of FIG. 1B) from the generator / motor (e.g., generator / motor 121 of FIG. 1A and / or generator / motor 185 of FIG. 1B), such that power may be provided to the generator / motor via the power I / O (e.g., power I / O 125 of FIG. 1A) to drive the generator / motor as a motor and provide mechanical power to the power shaft (e.g., power shaft 111 of FIG. 1A and / or clutch output / power shaft 180). That is, in the fourth mode, only the generator / motor may provide power (electricity) to the propulsion mechanism based on the power received at the power I / O.

[0046] In a fifth mode, which may be referred to herein as an engine power split mode, a clutch (e.g., clutch 115 of FIG. 1A and / or clutch 175 of FIG. 1B) may engage an engine (e.g., engine 105 of FIG. 1A and / or engine 155 of FIG. 1B) with a generator / motor (e.g., generator / motor 121 of FIG. 1A and / or generator / motor 185 of FIG. 1B), such that the engine may not only rotate the generator / motor as a generator to provide power to other systems on the aircraft via the power I / O (e.g., power I / O 125 of FIG. 1A), but may also provide mechanical power to a power shaft (e.g., power shaft 111 of FIG. 1A and / or clutch output / power shaft 180) to drive a system such as a propeller. That is, in the fifth mode, the engine may be used to drive a power shaft and generator / motor to output power (electricity) via the power I / O and power shaft. In various embodiments, the fifth mode can be achieved using a system without a clutch (eg, the system of FIG. 8B).

[0047] As described herein, any of these five modes (or variations thereof) may be used with the single flexible architecture described herein. Additionally, certain modes and / or combinations of modes may be beneficial for certain aircraft or aerospace vehicle types, certain propulsion types, certain flight phases of an aircraft or aerospace vehicle, etc. In any of these modes that use an electric machine (e.g., generator / motor, etc.) to generate a large amount of power, the electric machine may generate a large amount of heat. For example, if the electric machine is generating 10-100 percent (%) of the power output from the engine as electrical power, the electric machine may also generate significant heat. This includes instances where the electric machine is generating any of 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100 of the energy from the engine as electrical energy, including any instances where the electric machine is generating more than half (e.g., majority, 50-100 percent) of the energy from the engine as electrical power. In such cases where the electric machine generates significant heat, it may be beneficial to use a cooling system as described herein to cool the electric machine.

[0048] For example, in a hybrid electric vertical take-off and landing (VTOL) aircraft with electric motor-driven propellers, the flexible architecture herein may be used only as a power source such that the flexible architecture can power the aircraft in a first mode (e.g., hybrid generator mode) during any portion of the flight phase in which the aircraft's power bus or one or more of the aircraft's motors must be powered.

[0049] In another example, in an aircraft with a single large main pusher propeller (e.g., at the rear of the aircraft fuselage) and an array of electric motors / propellers (e.g., on the aircraft wings), the flexible architecture can be used in a fifth mode (e.g., engine power split mode) during takeoff to mechanically power the main pusher propeller and electrically power the wing-mounted motors. Figures 3 and 4 show two examples of such aircraft 300 and 400 that can use the flexible architecture for aerospace hybrid systems according to exemplary embodiments. For example, aircraft 300 has a main pusher propeller 305 and aircraft 400 has a main pusher propeller 405 in the form of a ducted propulsion fan. In both examples, the fifth mode described herein can be used to mechanically power the main pusher propellers 305 and 405 from a power shaft. Additionally, the wing-mounted electric motors / propellers 310 and 410 can be driven with electrical power from a motor / generator as described herein.

[0050] Alternatively, the flexible architecture described herein may be used to power configurations such as those shown in Figures 3 and 4 in a third mode (e.g., augmented mode) by the battery pack powering both wing-mounted motors at takeoff to augment engine power to the power shaft driving the main propulsion propeller. During cruise flight, the aircraft may use the second mode (e.g., direct drive engine mode) to drive only the main propulsion propeller. In another example, during cruise flight, the aircraft may include a clutch between the power shaft and the propulsion propeller, and the controller may operate the aircraft in a first mode (e.g., hybrid generator mode) driving the wing-mounted motor by disengaging the power shaft from the propulsion propeller and outputting power from the generator / motor to the wing-mounted motor. In another example (e.g., emergency situations such as engine failure), the propulsion prop may be driven in a fourth mode (e.g., direct drive generator / motor mode) using power input to a power I / O such as one or more batteries.

[0051] In another example, the aircraft may be a VTOL aircraft with a gyrocopter-type main rotor, which may operate powered or unpowered, and may have wing-mounted forward thrust motors and propellers. In one embodiment, the flexible architecture may be used entirely in a first mode (e.g., hybrid generator mode) where power provided from the power input / output (and generator / motor) drives motors coupled to the gyrocopter-type main rotor, and the power is used to drive wing-mounted motors. In one embodiment, the aircraft may be configured with a clutch between the power shaft and the gyrocopter-type main rotor such that the flexible architecture may use a second mode (e.g., direct drive engine mode) or a third mode (e.g., augmented thrust mode) to spin the gyrocopter-type main rotor (e.g., to bring the gyrocopter-type rotor up to takeoff speed). In such an example, the controller may switch the flexible architecture to the first mode (e.g., hybrid generator mode) after the gyrocopter-type rotor has reached speed (e.g., switch to the first mode for cruise flight). A fourth mode (e.g., direct drive generator / motor mode) can be used again in the event of engine failure, using electrical power to drive a powered shaft (and thus a gyrocopter-type rotor) from a power source such as one or more batteries.

[0052] 5 illustrates another example aircraft 500 that may employ a flexible architecture for an aerospace hybrid system, according to an example embodiment. For example, the aircraft 500 may include multiple (e.g., eight) electric motor / propellers 505 on a tilt wing that may be powered using a first mode (e.g., hybrid generator mode) described herein, in which an engine may be engaged with a power shaft using a clutch to drive a generator / motor that may output power to the various electric motor / propellers 505 on the tilt wing.

[0053] Thus, described herein is an advantageous flexible architecture for an aircraft that can achieve various modes for powering the propulsion. While a particular aircraft and propulsion configuration may not utilize each of the modes described herein for which the flexible architecture is capable, the flexible architecture can still be implemented in different aircraft to achieve different modes. Similarly, while one example of a flexible architecture having five different modes for powering the propulsion is described in detail herein, other flexible architectures having fewer, more, or different modes for powering the propulsion are also contemplated herein.

[0054] For example, a flexible architecture may not have a clutch as described herein, but may still achieve the various modes described herein when it is desirable to couple the engine output to the motor / generator and / or power output shaft of the system. For example, in a first mode, the engine may rotate a power shaft to generate electricity via a generator. In a second mode, the engine may directly drive, for example, mechanical propulsion components, but it is not necessary to disengage the engine from the motor / generator or power shaft because the motor / generator may be turned off or the motor / generator power shaft and rotor may be allowed to freewheel within the motor / generator. In a third mode, the engine and motor / generator are used to drive the power shaft, so it is not desirable to disengage the engine and motor / generator using a clutch. In a fifth mode, the engine may rotate a power shaft to generate electricity via a generator, which mechanically powers the propulsion mechanism. Thus, in an aircraft utilizing any of the first, second, third, and / or fifth modes described above, it is not necessary to disengage the power shaft from the engine output. Thus, in embodiments using any combination of the first, second, third, and / or fifth modes (but not the fourth mode), a clutch may not be used since the system may always connect the engine output to the motor / generator power shaft, which may be of value since clutches may be heavy and / or unreliable.

[0055] 6 is a flow chart illustrating a first exemplary method 601 for using a flexible architecture of an aerospace hybrid system in different flight phases of an aircraft with a main propulsion propeller, according to an exemplary embodiment. In particular, the aircraft may be an aircraft with a single larger propulsion propeller and an array of electric motors and corresponding smaller propellers on the wings. During the takeoff flight phase at 602, the fifth mode described herein may be used to mechanically power the main propulsion propeller and to provide electrical power to the wing-mounted motors. During the cruise flight phase at 604, the second mode described herein may be used to mechanically power only the main propulsion propeller and not provide electrical power to the smaller electric motors / propellers.

[0056] FIG. 7 is a flow chart illustrating a second exemplary method 700 for using a flexible architecture of an aerospace hybrid system in different flight phases of an aircraft with a main propulsion propeller, according to an exemplary embodiment. In particular, the aircraft may be an aircraft with a single larger propulsion propeller and an array of electric motors and corresponding smaller propellers on the wings. During the takeoff flight phase at 702, a third mode described herein, called thrust augmentation, may be used to power the main propulsion propeller via a generator / motor (drawing power from the battery) and to mechanically power the main propulsion propeller directly from the engine. Additionally, power (generated by the generator / motor and / or generated directly from the battery) may also be provided to the electric motors on the wings during takeoff. During the cruise flight phase at 704, a second mode described herein may be used to mechanically power only the main propulsion propeller and not the smaller electric motors / propellers.

[0057] 1A , when engine 105 applies power to power shaft 111 and clutch 115 is engaged such that generator / motor 121 is not running or turned on, power shaft 111 may freewheel within generator / motor 121 (e.g., in the second mode described above). Similarly, power shaft 180 of FIG. 1B may freewheel within generator / motor 185 in various embodiments. However, engine 105 and / or engine 155 may generate torque pulses on power shaft 111 and / or power shaft 180 that may be dangerous to generators such as generator / motor 121 and / or generator / motor 185 when clutch 115 and / or clutch 175 engage the respective power shafts 111 and / or 180. In other words, a large torque pulse on the shaft, similar to that which can occur when certain types of engines (e.g., diesel piston internal combustion engines) fire, can cause high angular accelerations that can cause fatigue or damage to the components of the generator / motor 121 and / or generator / motor 185 coupled to the power shafts 111 and / or 180. As such, components to mitigate this torque can smooth the torque on the power shafts 111 and / or 180, such as using a flywheel or other heavy damping or spring coupling system.

[0058] FIG. 8A illustrates an example of a flexible architecture 800 for an aerospace hybrid system having a flywheel for absorbing vibration torque, according to an exemplary embodiment. In particular, the flexible architecture 800 includes similar or identical components as those shown in and described with respect to FIG. 1B, but includes a flywheel 195 rigidly connected to an output flange 165 using bolts 170. The flywheel 195 is further rigidly connected to one side of a clutch 175 by bolts 198. Thus, rotational motion can be transferred from the engine 155 through the crankshaft 160, the output flange 165, and the flywheel 195 to the clutch 175. The clutch 175 can engage or disengage the power shaft 180 to selectively transfer the rotational motion received from the flywheel 195 to the power shaft 180. The flywheel 195 can also be, for example, a dual mass flywheel or a spring coupling.

[0059] In various other embodiments, a flywheel may not be used. For example, further embodiments of damping systems and damping devices are described herein that may dampen torque on a power shaft (e.g., power shaft 111) but do not include a flywheel. Additionally, in various embodiments, a flywheel and other damping systems or components may be used in combination to dampen or smooth the torque applied to the power shaft.

[0060] For example, a power shaft or rotor within the generator / motor itself may be rigidly coupled to the crankshaft of the generator / motor. In this manner, the crankshaft and rotor may together dampen torque pulses on the power shaft or rotor, reducing tangential acceleration due to torque pulses from the engine. In such an embodiment, a clutch may be omitted. As such, the damping system is internal to the generator / motor, and the damping system's footprint and weight may be smaller than a flywheel or other damping system that may be external to the generator / motor. In particular, a rigid coupling of the power shaft or rotor to the crankshaft may increase the inertia of the power shaft or rotor, whereby that additional inertia helps to prevent the power shaft from slowing down or otherwise rotating in a manner that is susceptible to acceleration due to torque pulses of the engine. In such an embodiment, the power shaft or rotor and crankshaft may function similarly to a flywheel.

[0061] In various embodiments, a generator / motor may be used that has a stationary inner portion and a rotating outer portion, which increases the inertia of the rotating portion and may allow magnets in the generator / motor to rotate and avoid being dislodged by the Torx spike. In other words, since the magnets may already be rotating on the outer portion, a constant stabilizing radial force may be applied in addition to the tangential inertial force due to the torque spike acceleration.

[0062] The torque damping system may also be configured as part of the power shaft or rotor that connects the engine output to the generator / motor. For example, the hub between the generator / motor power shaft or rotor may include a coupling with torsional spring and / or damping properties. The torsional damping coupling may include an elastomeric part or spring (e.g., made of steel or another metal) that reduces the transmission of potentially harmful torque impulses from the engine output to the generator power shaft or rotor. The torsional damping coupling may be similar to or referred to as a resonant damping coupling. For example, such a torsional damping coupling may reduce the weight and size of the overall system as opposed to a system that uses a flywheel or other bulky damping system. One or more torsional damping couplings may be installed in the engine, between the engine and the clutch, in the clutch, between the clutch and the generator, and / or in the generator to achieve damping before the power shaft or rotor damages components of the generator itself.

[0063] Other methods of damping torque on the generator's power shaft or rotor may also be used. For example, the magnetic field on the generator may be pulsed and controlled to act on the generator's power shaft or rotor to counter some or all of the torque pulses imparted to the power shaft or rotor by the engine. Such pulses on the generator's magnetic field may be controlled based on measurements of torque pulses applied by the engine, so that generator components are not damaged by the diesel engine. For example, in the third mode described above, where both the engine and the generator / motor provide power to the power shaft, pulses may be provided from the generator to the power shaft to provide power to the power shaft and prevent generator components from being damaged. In other modes described herein, the generator may be used to apply pulses to the power shaft whenever the power shaft is being driven in part by the engine overall. Thus, to adequately protect generator components in such a manner, the pulses applied by the generator's magnetic field to the power shaft or rotor may be configured to correlate with and appropriately counteract the torque pulses of the engine.

[0064] FIG. 8B illustrates an example of a flexible architecture 1400 for an aerospace hybrid system with a flywheel and spring coupling to absorb vibration torque, according to an exemplary embodiment. In particular, the flexible architecture 1400 includes similar or identical components as shown in and described with respect to FIG. 8A, but includes a spring coupling 199 rigidly connected to the flywheel 195 and the power shaft 180. The size, weight, etc. of the flywheel 195 and the characteristics of the spring coupling 199 can be adjusted according to the output of the engine 155 and the characteristics of each other, so that the vibration torque can be reduced as desired and / or as possible. For example, different engines may generate different amounts of vibration torque, so various embodiments herein include flywheels and / or spring couplings with different characteristics to reduce vibrations transmitted from the crankshaft 160 to the power shaft 180. In various embodiments, the flexible architecture 1400 may not have a clutch, such that the crankshaft 160 and the power shaft 180 are always coupled to each other. In various embodiments, a flexible architecture similar to that of FIG. 14 may also include a clutch such that the output of the engine 155 can eventually be releasably disengaged from the power shaft 180. In various embodiments, such a clutch may be connected between the spring coupler 199 and the power shaft 180, or the power shaft may be split into multiple shafts with clutches connected to the multiple shafts, or the clutch may be located anywhere between the engine 155 and the generator / motor 185 such that the output of the engine 155 can be selectively disengaged from the portion of the power shaft 180 that travels through the generator / motor 185. In various embodiments, a clutch may additionally or alternatively be located after the generator / motor 185 such that the power shaft 180 can be disengaged from the load (e.g., the propulsion system of the aircraft).

[0065] Further, examples of how the flexible architectures described herein can be packaged and / or used in actual aircraft are described below. For example, certain aircraft may use electric motors to drive their propulsion systems and therefore must have sufficient on-board electrical energy to drive those propulsion systems or be provided with a method to generate such on-board electrical energy. Furthermore, regulations in certain jurisdictions may require sufficient reserve energy to comply with aircraft operating regulations. The flexible architectures described herein can provide such electrical energy and / or reserve energy to the propulsion systems such that the systems described herein can operate in a variety of electric aircraft. For example, embodiments herein provide efficient conversion of jet fuel (or other liquid or gas fuels) to electricity such that widely available fuel sources can be used to power electric aircraft.

[0066] Figure 23 illustrates a perspective view 2300 of an example flexible architecture of an aerospace hybrid system, according to an exemplary embodiment. This hybrid unit can be used as a core powerplant for a variety of aircraft types and implementations. The hybrid unit of Figure 23 is a tightly integrated powerplant that may include some, all, and / or additional elements shown and described in Figures 1A, 1B, 2A, 2B, and / or 8A / 8B.

[0067] Additionally, the hybrid unit may include an integrated cooling system 2305 for cooling various aspects of the hybrid unit, heat exchangers associated with the hybrid unit, or heat sinks such as finned attachments on any aspect of the hybrid unit. The power output 2310 may be or may connect to a power shaft (e.g., power shaft 110 of FIG. 1A, power shaft 180 of FIG. 1B or FIG. 8A / FIG. 8B) such that rotational power may be output from the hybrid unit to a propulsion system or other aspects of the aircraft. The electrical connector 2315 may be used to output electrical power (or input electrical power) as described herein. The electrical connector 2315 may be, for example, an Amphenol Surlok Plus™ connector or equivalent, or any other type of suitable connector. In this manner, a main bus, such as a direct current (DC) bus of the hybrid unit, may be connected via the electrical connector 2315 (e.g., power input / output 125 of FIG. 1A, power I / O 245 of FIG. 2A or FIG. 2B). These or other connectors may also facilitate connection and control of components of the hybrid unit, such as through the use of a Controller Area Network (CAN) bus, a CAN 2.0 bus, and / or an SAE J1939 bus. Such communication buses may operate at different speeds, such as 250 kilobytes per second (kbps), 500 kbps, 1000 kbps, etc. In various embodiments, the electrical connector 2315 and / or other connectors may be customized for specific applications, such as different types of aircraft and the communications and power systems they use.

[0068] By virtue of the power output 2310 and electrical connector 2315, the hybrid unit of FIG. 9 can output mechanical power via the power output 2310 and / or output electrical power via the electrical connector 2315 and a DC bus (e.g., power input / output 125 of FIG. 1A , power I / O 245 of FIG. 2A or FIG. 2B ) within the hybrid unit. Similarly, just as mechanical power is received via the power output 2310 to generate electricity for output via the electrical connector 2315, electrical power can be received via the electrical connector 2315 to drive the power output 2310. For example, if the aircraft includes one or more batteries, additional electrical power from the batteries can be received via the electrical connector 2315 to boost the power (electrical power) applied to the power output 2310, such that the power output 2310 is driven by both the engine and electrical power from the aircraft's batteries, as described herein.

[0069] The hybrid unit of FIG. 23 may further include a connector 2325 for connecting the engine to a fuel source. The connector 925 may be a quick fuel connection, such as an AN6 quick fuel connection. In this manner, the engine may be supplied with fuel to power the power output 2310 and / or generate electricity that is output via the electrical connector 2315. The hybrid unit of FIG. 23 may further include mounting hardware 2320 for mounting the hybrid unit to an aircraft. Although the mounting hardware 2320 is shown on the top of the hybrid unit in FIG. 23, in other embodiments, the mounting hardware may additionally or alternatively be located on either the top, bottom, side, etc. of the hybrid unit such that the hybrid unit may be mounted to the aircraft as desired.

[0070] Figure 24 illustrates a top view 2400 of the example flexible architecture of Figure 23 in accordance with an exemplary embodiment. Figure 25 illustrates a side view 2500 of the example flexible architecture of Figure 23 in accordance with an exemplary embodiment.

[0071] Thus, the hybrid units described herein can be used to power electric or hybrid electric aircraft and can provide better power than battery packs alone. For example, hybrid units such as those shown in FIGS. 23-25 ​​can provide better energy density than batteries (e.g., 5-7 times better energy density). For example, the hybrid units described herein can have an equivalent energy density of 600-1200 or more watt-hours per kilogram (Wh / kg). Additionally, the hybrid units described herein advantageously have better fuel economy than other systems (e.g., 40% better fuel economy than turbine engines) and can use readily available fuels such as Jet-A, diesel, kerosene, biofuel alternatives, or other suitable or desired fuels. In other words, the hybrid units herein can include an engine using air cooling, a generator, an inverter, and thermal management in a compact package, thereby allowing aircraft equipped with a flexible architecture to advantageously utilize these components as power generation equipment. Various voltage outputs (e.g., 400 volts (V), 800V, 1000V, 1200V, etc.) are provided from the hybrid architecture, as well as connections for other accessory or system power (e.g., 28V). The flexible architecture described herein can be quieter than other systems (e.g., quieter than turbine engine systems). For example, noise levels can be less than 70 decibels (dB) at distances of 100 feet or less from current systems.

[0072] The flexible architecture described herein may also be scalable. For example, a larger aircraft may use two or more of the flexible architectures described herein. The flexible architecture may also be used for a variety of aircraft designed for different functions and purposes. For example, the flexible architecture described herein may be useful in Urban Air Mobility (UAM) systems such as electric vertical take-off and landing (eVTOL) aircraft, electric short take-off and landing (eSTOL) aircraft, conventional electric take-off and landing (eCTOL) aircraft, etc. One example of a flexible architecture such as that shown in Figures 23-25 ​​may have the specifications shown in Table 1 below. [Table 1] *Maximum burst shaft power depends on battery configuration. **Dry mass includes engine, generator, inverter, and thermal system.

[0073] As shown above, a 185 kW hybrid unit may be provided, and thus two hybrid units may be provided on a particular aircraft to provide 370 kW of power.

[0074] Figure 26 illustrates a perspective view 2600 of another example of a flexible architecture for an aerospace hybrid system, in accordance with an illustrative embodiment. The flexible architecture of Figure 26 includes an engine 2605 and a generator, which are hidden or not visible due to other components of the system, such as cooling ducts. However, similar to the hybrid units of Figures 23-25, a mechanical power output 2610 and an electrical power output 2620 (both of which can optionally receive electrical power (motive power) as well) are provided.

[0075] Thus, various embodiments herein provide a hybrid power plant that can be integrated into a variety of different types of aircraft in the aerospace market. In doing so, aircraft manufacturers may not need to build their own systems of engines, generators, power electronics, cooling systems, and / or control systems to power the aircraft. This can be advantageous because the development process to create a power generation system and meet aerospace standards can take at least four years and cost $10 million or more.

[0076] In this manner, the hybrid power plant or flexible architecture described herein may be designed, manufactured, etc., separate from the design of the aircraft. Some aspects of the flexible architecture may be customized according to the desires of the aircraft manufacturer, but in a manner that does not result in a redesign or reconfiguration of the entire system. Thus, embodiments herein provide an integrated unit that includes an engine, generator, power electronics, cooling system, and / or control system in one package that is installed on the aircraft. Combining these elements into a single standalone unit may further advantageously allow the unit to go through the Federal Aviation Administration (FAA) certification process as a system. This would allow multiple aircraft manufacturers to use the certification system, reducing the certification burden and development burden on aircraft developers, as well as improving efficiency by eliminating the need for multiple aircraft manufacturers to certify many different power generation systems designed specifically for their aircraft.

[0077] By providing a combined unit with engines, generators, power electronics, cooling systems, and / or control systems, the hybrid flexible architecture described herein can be optimized as an entire system rather than as separate components. Optimize the whole system rather than optimizing the parts. Furthermore, such hybrid units can be used in multiple aircraft designs, but the systems designed as part of the aircraft design process are configured in a way that makes them difficult to reapply elsewhere. Having a hybrid unit that can be applied to multiple market segments and aircraft designs with common power requirements expedites the development of production aircraft, with major components of the aircraft already certified (e.g., hybrid units or flexible architectures, etc.).

[0078] Aviation hybrid electric systems have historically been designed from the ground up for each application / aircraft. Such a process is inefficient and is addressed by embodiments herein. For example, some aircraft are equipped with unique power generation equipment designed specifically for that aircraft. Such solutions may include custom engines, generators, power electronics, control systems, cooling systems, battery packs, propulsion motors, and / or propellers. Embodiments herein provide a compact hybrid system for an aircraft that may constitute two separate halves within an aircraft's power and propulsion system, i.e., one half of the upstream end and one half of the downstream end of a powertrain (such as the hybrid powertrain described herein).

[0079] 27 illustrates examples of downstream components 2705, 2710 and upstream components 2715, 2720 for propelling an aircraft 2700, according to an exemplary embodiment. For example, the downstream components 2705, 2710 of an aircraft system may include motors, rotors / propellers, attitude control components, etc., as may be relevant depending on the particular design of the aircraft. The upstream components 2715, 2720 of the aircraft, which may be repeatable within different aircraft, may include any of the engines, generators, batteries, power distribution, fuel, generator noise abatement, etc.

[0080] Specifically, the upstream end of the powertrain may include hybrid powertrain elements responsible for generating electrical power. Such components may include an engine, a generator, power electronics, a control system (for the upstream power generating components), a cooling system (for the upstream components), a battery pack, and / or fuel. The downstream end of the powertrain may include hybrid powertrain elements responsible for converting electrical power into thrust, attitude control, and / or active control of aerodynamics. These downstream components may further include electric motors, propellers, motor controllers, and / or control systems for the propulsion system.

[0081] Thus, there may be a need for a common upstream powertrain across very different electric aircraft designs with similar size and total power requirements. However, because downstream powertrains have little consistency between aircraft, these components may not be standardized to work across many aircraft designs as the upstream components. Furthermore, upstream elements that aid in standardization may include components related to power requirements rather than total energy requirements. In the case of engines, generators, power electronics, cooling systems, and / or control systems, these elements of the upstream powertrain may be sized to fit the specific power requirements (kW or hp) of the aircraft. However, the amount of fuel and the size of the battery pack may be determined by the total energy requirements (kWh or hp hr), which may vary from aircraft to aircraft. In such an embodiment, the volume of fuel may be adjusted by changing the size of the fuel tank to fit the requirements of the aircraft design, and the capacity of the battery pack in kWh may be adjusted by adjusting the number of parallel stacks of cells in the battery pack or by adding additional battery packs.

[0082] Accordingly, embodiments are provided herein for providing a hybrid power plant that tightly integrates an engine, generator, power electronics, control system (for the power plant), and / or cooling system in a weight- and space-efficient manner, such that the hybrid power plant can be certified as a stand-alone unit that is separable from the aircraft and designed to provide propulsion.

[0083] Additionally, as described herein, the rotor in the generator can be optimized to serve multiple purposes in the context of a hybrid power plant. A conventional internal combustion engine may have a flywheel mass attached to the rotating shaft to enhance smoothness of operation. However, in the context of an aerospace system, adding extra mass may be undesirable. As described herein, when an engine is coupled to a generator in a hybrid power plant, the rotor of the generator may be designed to withstand torque impulses from the engine and to be the rotating mass that the engine utilizes to smooth operation.

[0084] Additionally, while auxiliary power units are known in the art, these systems may be designed for purposes other than as the primary propulsion source for an aircraft and therefore may not have a control system that can be certified to standards required for use in propulsion. Additionally, such systems may be designed without a cooling system, which is left to the airframe designer. As such, these systems are not Part 33 certified. Additionally, these auxiliary power unit systems are designed as light-weight auxiliary systems that are used intermittently, rather than as highly efficient propulsion systems used during all phases of flight. Additionally, while auxiliary power units may be designed to generate alternating current (AC) power, the hybrid power plants described herein are capable of generating direct current (DC) power, and therefore the hybrid power plants may be coupled to large propulsion battery packs, as the battery packs are powered and charged using a DC power source.

[0085] Turbogenerators are one type of adaptive auxiliary power unit proposed for hybrid power. Such systems lack cooling system integration that provides airframe developers with a cooling system that is part of the hybrid power plant. As such, airframe developers may need to design their own cooling system associated with the use of a turbogenerator. Using embodiments herein may be advantageous in that a separate cooling system for cooling the hybrid power plant described herein does not need to be designed or developed for a particular airframe, since such a cooling system is already included in the flexible architecture described herein.

[0086] As such, the flexible architectures and hybrid power plants described herein advantageously provide an engine for converting liquid fuel (or gaseous fuel) into rotary mechanical power, a generator coupled to the engine configured to convert the rotary mechanical power into electricity, and / or power electronics coupled to the generator configured to convert a direct AC output of the generator into high voltage DC power. The flexible architectures and hybrid power plants described herein further advantageously provide a control system configured to vary the power output of the engine to match the power demands of the aircraft's main propulsion electric bus to meet the power demands of the aircraft.

[0087] The hybrid powerplant control system, power electronics, generator, and / or engine designs described herein may further comply with regulatory requirements for the reliability of aerospace propulsion systems (e.g., probability of failure is 10 -6or 10 to the power of minus 6). The flexible architectures and hybrid powerplants may further include a control interface that allows the flexible architecture or hybrid powerplant to communicate with a vehicle level flight control system to provide propulsion commands from the vehicle level flight control system to the hybrid powerplant control system, which may also advantageously provide for the hybrid powerplant control system to send status messages back to the vehicle level flight control system (e.g., feedback for use in controlling the flexible architecture or hybrid powerplant). The flexible architectures and hybrid powerplants may further include a cooling system that maintains temperature ranges of the generator, power electronics, and / or engine throughout the full range of operating power outputs of the flexible architectures and hybrid powerplants described herein.

[0088] Various embodiments of the flexible architecture or hybrid power plants described herein may further include a control system that varies the power output by varying the engine torque and / or maintains a substantially constant revolutions per minute (RPM) over a significant range of the power output. Such embodiments may provide faster response of the flexible architecture or hybrid power plant by eliminating throttle lag and longer response times associated with the rotational inertia of the system.

[0089] Various embodiments of flexible architecture or hybrid power plants described herein may further include an option to provide a portion of the engine's power output as mechanical shaft power and a portion as DC power. Various embodiments of flexible architecture or hybrid power plants described herein may further include embodiments in which the engine may be a piston engine, a diesel piston engine, a turbine engine, a rotary engine, or other form of combustion engine. Various embodiments of flexible architecture or hybrid power plants described herein may further include examples in which the rotor of the generator is designed to be the flywheel of the engine. Various embodiments of flexible architecture or hybrid power plants described herein may further include a clutch between the engine and the generator so that the generator can be operated as a motor while the engine is shut down in some types of parallel hybrid installations described herein.

[0090] As further described below with respect to Figures 9-21, various embodiments described herein also provide for simultaneous air cooling of multiple elements of a hybrid power plant, such as the hybrid flexible architectures described herein. For example, the engine (e.g., a piston engine, a rotary engine, a turbine engine, etc.), the electric machine (e.g., a generator, a motor, or a generator / motor as described herein), the power electronics, and / or the engine intake of a hybrid system may all be advantageously efficiently and simultaneously cooled by the cooling systems described herein. In this manner, disparate components of a hybrid power plant with separate cooling components may be linked with a combined air cooling system that may reduce aircraft weight and increase aircraft reliability.

[0091] Various embodiments of the cooling system described herein utilize air cooling so that air is supplied to different aspects or components of the hybrid power plant. Air is lighter than other media used for cooling, such as water. Thus, the embodiments described herein may have a weight advantage over other systems, such as systems that use liquids, such as water, as the primary medium for cooling. In addition to being heavier than air-based systems, water-cooled systems may face icing issues, especially in aircraft that may operate at high altitudes and thus be exposed to low temperatures.

[0092] Exemplary embodiments advantageously connect a fan, impeller, and / or blower to a power shaft or crankshaft of a flexible architecture described herein (e.g., power shaft 111 of FIG. 1A, crankshaft 160 of FIG. 1B, power shaft 180 of FIG. 1B), whereby the fan, impeller, and / or blower are mechanically driven based on power provided to the power shaft or crankshaft by an engine of a flexible architecture described herein (e.g., engine 105 of FIG. 1A, engine 155 of FIG. 1B) or generator / motor (e.g., generator / motor 121 of FIG. 1A, generator / motor 185 of FIG. 1B). As such, fans, impellers, and / or blowers are configured to provide air cooling directly from mechanical power received from a rotating power shaft and / or crankshaft, and may supply air to multiple system elements for cooling, including supplying air directly to the components for cooling or supplying air to one or more heat exchangers or finned heat sinks used to cool other components (e.g., components with their own liquid cooling systems).Unless otherwise noted, it should be understood that the terms fan, blower, and / or impeller may be used individually to refer to any of the fans, blowers, impellers, or other similar components, and any combination of such elements. In various embodiments, instead of a single fan, impeller, and / or blower, multiple fans, impellers, and / or blowers may be connected to the shaft directly or indirectly (where indirectly, via one or more gearboxes, pulleys, torque converters, or other power transmission methods, where there may be a single gearbox or torque converter or one of each of the fans, impellers, and / or blowers) to direct air to different components of the flexible architecture and / or cooling system described herein.

[0093] The embodiments described herein provide a lighter weight system than systems that use separate cooling for individual components of the flexible architecture. Additionally, the embodiments herein can reduce conversion losses that may occur in systems that convert mechanical power to electrical power to drive electric fans, since mechanical power from the power shaft or crankshaft can be provided directly to drive the fan. Thus, mechanical power from the flexible architecture is directly converted to air cooling flow. The embodiments described herein further provide a lighter weight and more efficient system, since the cooling fan and associated ductwork can be tightly coupled or located relative to the rest of the flexible architecture, thereby resulting in an efficient, lightweight and compact system for powering an aircraft. The embodiments also increase efficiency by reducing the distance between the cooling inlet of the air cooling system and the device or component being cooled.

[0094] 9 illustrates a schematic diagram of an example cooling system for a hybrid power plant according to an exemplary embodiment. The hybrid power plant may be any of the flexible architectures described and / or illustrated herein, for example, as shown in and discussed with respect to FIGS. 1-8.

[0095] The cooling system of FIG. 9 includes a blower 902 that is powered directly via mechanical energy from a shaft passing through a generator / motor 914. The shaft may also be connected to an engine 904. In this manner, the shaft may be driven by one or both of the generator / motor 914 and the engine 904. The engine 904 may be a piston engine, a turbine engine, a rotary engine, or other type of combustion engine or other engine. An inverter 912 may further be attached to the generator / motor 914, whereby electrical power may be generated from the rotation of the shaft, or electrical power (e.g., from a battery pack or other power source) may be input to the generator / motor 914 and used to rotate the shaft. The engine 904 may further include a cylinder 906, oil for an oil cooling system 908, and a turbocharger 920. An air charge cooler 918 may further be included in the system to cooperate with the turbocharger 920. The system further includes an oil cooler 916 and various hardware 910 (e.g., control or other electronics).

[0096] The blower 902 is configured to be rotated by an engine 904 and / or a generator / motor 914 which rotates a shaft to which the blower 902 is connected. Cool air from the blower 902 may be channeled through various ducting structures to the motor / generator 914, various hardware 910, a cylinder 906 of the engine 904, an oil cooler 916 (e.g., a heat exchanger), a charge air cooler 918 (e.g., a heat exchanger), or other components requiring cooling. In various embodiments, some of the components to which the air is channeled may be or include a heat exchanger (e.g., an air-to-air heat exchanger, an air-to-fluid heat exchanger), whereby the air from the blower 902 may be used to indirectly cool the component via the heat exchanger. In various embodiments, any of the components of FIG. 9 or part of the flexible architecture may include a heat sink element, such as a set of fins, configured to sink heat from the component to the air from the blower 902. As such, the components may be indirectly cooled via a heat sink mechanism, which is in contact with the cooling air from the blower 902. In various embodiments, a combination of a heat exchanger and a heat sink (e.g., fins) may be used to cool the components. For example, the heat sink element may reject heat to the air or fluid on a first side of the heat exchanger, and air from the blower 902 may be directed to a second side of the heat exchanger to remove heat from the air or fluid on the first side of the heat exchanger.

[0097] Thus, the blower 902 can be used to cool various components of the flexible architecture, as described further herein. For example, air from the blower 902 can be directed to an oil cooler 916, which is an air-to-fluid heat exchanger configured to exchange heat between the air from the blower 902 and oil in the oil cooler 916. The cooled oil from the oil cooler 916 can then be circulated into an oil cooling system 908 of the engine 904 to cool the engine 904 (e.g., remove heat from the engine 904 by transferring heat to the oil). The hot oil from the oil cooling system 908 can then be circulated back to the oil cooler 916 to be cooled again via the air from the blower 902.

[0098] Cool air may also be provided to the charge air cooler 918. Ambient air may enter the turbocharger 920, be compressed, and then output to the charge air cooler 918. Compressed air from the compressor inlet side of the turbocharger 920 may then be cooled in the charge air cooler 918 using air channeled from the blower 902 to the charge air cooler 918. In other words, the charge air cooler 918 may function as an air-to-air heat exchanger. The cool air may then be output from the charge air cooler 918 to the intake of the engine 904, for use in the combustion cycle of the engine 904, for example. The exhaust output from the engine 904 may then be channeled to the hot side of the turbine or turbocharger 920, which then discharges the air to the environment as exhaust. In this manner, the air used by the turbocharger and / or engine may ultimately be indirectly cooled using the air-to-air heat exchanger of the charge air cooler as part of the turbocharger cycle.

[0099] In this way, various components of a flexible architecture as described herein can be cooled. The cylinders (or rotors) of a diesel aircraft engine (e.g., a piston combustion engine) can be air-cooled or liquid-cooled. In the example of FIG. 9, the cylinder 906 is air-cooled. However, the cylinders may additionally or alternatively be liquid-cooled by adding a heat exchanger between the liquid of the cylinder liquid cooling system and the cold air provided by the blower 902. When a liquid coolant is used, the liquid may be, for example, a mixture of water and glycol. Similarly, the cylinder heads of an aircraft diesel engine (e.g., a piston combustion engine) can be air-cooled, oil-cooled, or water-glycol-cooled. Thus, the air from the blower 902 can be used directly or indirectly (using a heat exchanger or a finned heat sink) as well as the cylinders described herein. Other engines other than piston engines, such as turbine or rotary engines, may also include liquid or air cooling systems for their components and therefore may similarly benefit from the cooling systems described herein (e.g., through direct cooling via air from the blower 902, or a heat exchanger between the air from the blower 902 and a coolant of the engine or a separate cooling system associated with the engine).

[0100] Engine oil in an engine can also be cooled with the flexible architecture. In the example of Figure 9, oil 908 is circulated through an oil cooler 916, with heat exchange between the oil 908 and the cool air provided by the blower 902. The heat absorbed by the oil 908 in the engine 904 can come from bearing shear in the engine 904, and the oil can also be used for other cooling such as the cylinder head and / or piston (or rotor).

[0101] The charge (intake air) is typically air-cooled, which is required for turbocharging. Turbocharging is very common in aircraft to increase the range of altitudes that can be used with the power to handle the mission, and it also greatly improves the overall thermal efficiency of the engine. Compressing the intake air increases its temperature, and this temperature must be reduced before it is introduced into the cylinder to avoid problems associated with piston cooling, detonation, etc.

[0102] An electric motor / generator (also referred to herein as an electric machine), such as motor / generator 914 in Figure 9, may be cooled due to the presence of electrical resistance and current flow in the electrical and electronic components within motor / generator 914. This cooling may be accomplished by air cooling, such as from blower 902, or liquid cooling, such as via a heat exchanger supplied with air cooling from blower 902. Liquid cooling may be accomplished, for example, via a mixture of water and glycol or a dielectric (non-conductive) fluid.

[0103] An inverter (with associated power electronics), such as inverter 912 in Figure 9, may be cooled due to heat generated within electrical circuitry, such as high speed switches and other hardware therein. Such cooling may be accomplished via air cooling, such as from blower 902, or via liquid cooling, such as via a heat exchanger supplied with cold air from blower 902. Liquid cooling may be accomplished, for example, via a mixture of water and glycol or a dielectric (non-conductive) fluid.

[0104] Other elements of the hybrid power plant described herein may achieve passive cooling. In other words, the cooling requirements of system elements, including but not limited to clutches (if present), couplers, supervisory or other controllers, fan bearings / seals, etc., may be met by the normal use environment without active design features (fans, pumps, radiators) to enhance the cooling provided. In various embodiments, active cooling may be provided to any component of the aircraft as described herein, as needed, by air cooling, such as from blower 902, or liquid cooling, such as by a heat exchanger supplied with cool air from blower 902.

[0105] As discussed above, air or fluid systems may be used to cool various aspects of an aircraft. However, embodiments herein provide a reduced number of fluid cooling systems that may be used within an aircraft to cool various aspects of the aircraft. A fluid cooling system may use one or more pumps to circulate the fluid. Such pumps may be mechanical or electrical. In the case of mechanical pumps, there is weight and complexity associated with the pump. The pumps themselves must also be installed on the aircraft, increasing the weight and complexity of the aircraft. Pumps may also have bearings, seals, and / or plumbing fittings that may leak. If the pumps are powered by electricity, they may be rated for heat transfer and therefore require relatively high power (e.g., 5000 watts (W) or more).

[0106] The fluid system may be designed to accommodate expansion and contraction of the fluid during use, loss of air during system filling, drainage of the system during use or for other reasons, and / or loss of fluid during the design and / or operation of the aircraft. All of these factors can represent engineering complexities and certification challenges that may be advantageously avoided by using the air cooling systems described herein.

[0107] Fluid systems may also have issues with ice formation, such as at temperatures below -35° F. (-35° C.), which may cause the system to fail or become less efficient, or additional components may be added to avoid ice, further increasing the weight and complexity of the cooling system.

[0108] The fluid system may also use some type of heat exchanger. This may be fluid-to-fluid, transferring heat from a hotter fluid to a cooler fluid, or fluid-to-air, transferring heat to air exhausted overboard. In either case, each heat exchanger represents weight and volume (contributing to the overall weight of the flexible architecture / powerplant system and / or aircraft), represents several potential failure points where leaks may occur (at least two, plus spills and exhausts), and often includes welds that carry certain metal fatigue risks. While some heat exchangers may still be used in the embodiments described herein (e.g., to cool engine oil), it may be advantageous to reduce the number of heat exchangers and / or fluid cooling systems, as described herein.

[0109] In some example aircraft where the fluid cooling system uses a fluid-to-air cooler, depending on the design of the aircraft and the overall system, such systems may use dedicated fans to move the air to perform the desired heat transfer. Such fans may be electrically driven and therefore may require high powered motors rated for the heat transfer (e.g., 5000 W or more). As discussed above, pumps for the fluid system rated for high power may also be used when considering use in heat transfer applications.

[0110] The use of high power rated pumps and fans can be particularly disadvantageous for aircraft cooling systems. Many pumps, coolers, and fans are heavy, complex, take up a lot of space, and can cause multiple potential points of failure. In order to use electric pumps and / or fans to any degree, adequate power must also be provided to keep the cooling system running. For example, when an aircraft is conducting an extended mission (e.g., several minutes or more), stored energy (e.g., batteries) may not be sufficient to power such pumps and fans, and therefore a generator or other power source is provided. In some cases, such a generator may be an alternator mounted directly on the engine, or may be via a separate generator, or may be via one or more DC-DC converters. In particular, in aircraft featuring distributed electric propulsion with high voltage power for one or more lift or propulsion motors, it may be logical to use DC-DC to convert some of this high voltage power to a lower voltage used by the pumps and fans. However, such components add additional complexity and weight to the cooling system.

[0111] Any additional electrical circuits may have additional connections for power, ground, and control. These connections may be heavy and necessarily require size and rigidity (e.g., minimum bend radius), thus necessitating additional volume around the particular electronic device for safe connection and powering the device. Each device to be powered may also be equipped with short circuit protection components such as fuses or breakers that protect the device but may be resettable for safety reasons. The various electronic devices may also include components that provide safe handling for the service crew and / or in some cases control elements to adjust the function of the device to various parameters of the mission. Such components further increase the weight and complexity of the cooling system.

[0112] When DC-DC conversion is used and the voltage direction is from higher voltage to lower voltage, significant heat can be generated resulting in loss of efficiency and additional system elements requiring active cooling.

[0113] Additionally, copper conductors can be used wherever additional electrically powered equipment is added. Copper is often preferred for carrying electrical current in aircraft. The gauge (diameter of the wire) of copper is determined by a combination of the current being used and the local heat transfer available. Everything associated with the wiring can be heavy: the conductor, insulation, connectors at each end, physical support for the wire to prevent chafing, and / or additional armor applied to the wiring to prevent physical damage. Active heat transfer of the conductors and connectors may not be practical, so the size of the conductors may increase to keep temperatures low, resulting in increased weight. Therefore, it is also desirable to reduce the number of electrically powered equipment to reduce the weight and complexity of the system. Therefore, it is also desirable to reduce the number of components or systems that utilize fluid cooling in the aircraft.

[0114] Figure 10 illustrates an example of a hybrid power plant with a cooling system according to an exemplary embodiment. Figure 11 illustrates a cross-sectional view of an example of a hybrid power plant with the cooling system of Figure 10 according to an exemplary embodiment. Figure 12 illustrates a partial cross-sectional perspective view of an example of a hybrid power plant with the cooling system of Figure 10 according to an exemplary embodiment.

[0115] In particular, Figures 10-12 show together a cooling system that may be used in a hybrid power plant, where the cooling is directly driven by mechanical power, simultaneously providing cool air to various systems of the hybrid power plant, thereby achieving various benefits of reducing fluid cooling systems and electrical systems present in the aircraft. A generator / motor shaft may provide power from an engine 1010 and / or a generator / motor (not shown as it is in a housing 1014) to fan blades 1020. The shaft 1002 may provide power to mechanical components such as a propulsion mechanism such as a fan or a propeller. The air inlet 1004 receives ambient air, and the fan blades 1020 move the air through a duct structure 1006, 1012, 1013, 1016, 1018 and a shroud 1014 (e.g., annular). In the example of Figures 10-12, the fan blades 1020 are centrifugal blowers that direct air approximately perpendicular or perpendicular to the axis of the fan blades 1020. In various embodiments, axial and / or combination blowers may be used in addition to or in place of centrifugal blowers such as those shown in FIGS.

[0116] Because a blower, such as fan blades 1020, may be mechanically driven from the shaft 1002, there may be little or no conversion losses, and the power consumed may be measurable in terms of the pressure and flow of cooling air provided to cool other components of the system. In contrast, an electric fan requires no additional overhead, such as converting shaft power to electrical power (generation), converting voltage (DC-DC), transmitting electrical power (I 2 R losses), and possibly other losses.

[0117] 10-12 can simultaneously cool multiple devices and systems from a single shaft with airflow directing elements attached thereto, rotating at a set revolutions per minute (RPM). In various embodiments, multiple airflow directing elements (fans or blowers) can be attached to a single shaft, such as shaft 1002. In this manner, different airflow directing elements can direct different amounts of air in different directions, such as at different pressure levels, as described for a particular system or component.

[0118] Various embodiments can provide series or parallel cooling (or both) of various combinations of system components. The system shown in Figures 10-12 cools various components in parallel through different duct structures. Air can be introduced from fan blades 1020 into duct structure 1018 (point A in Figure 12) and travel through duct structure 1006 to heat exchanger 1008. Heat exchanger 1008 can be used as charge air cooler 918 or oil cooler 916, for example. In Figures 10-12, both a charge air cooler (or other air-induced heat exchanger) and an oil cooler can be present, but only one of those components is visible in the views of Figures 10-12, while the other is not visible from the view (although partially visible in Figure 10 as heat exchanger 1030). The heat exchangers 1008 and 1030 may be connected to a ductwork 1018 that includes two separate ducts, only one of which (eg, ductwork 1006) is shown in FIGS.

[0119] Air may be introduced from the fan blades 1020 into the duct structure 1016 (point B in FIG. 12) and pass through the duct structures 1012 and 1013 to cool the cylinders of the engine 1010 (similar to cylinders 906 in FIG. 9). A shroud 1014 may be disposed over or around an electric machine (e.g., a generator motor) and may function as a duct structure to provide cool air for cooling such an electric machine. Air may be introduced from the fan blades 1020 into the shroud 1014 (point C in FIG. 12) and pass through the shroud 1014 (e.g., to cool the motor / generator 914 and / or inverter 912 in FIG. 9). Thus, in FIGS. 10-12, a single centrifugal blower may be shaft driven using power from the engine crankshaft or power shaft to allow cooling air to flow into the blower parallel to the axis of rotation. The air then moves radially outward and is collected by three volutes A, B, and C arranged side-by-side around the blower wheel.

[0120] 12, section A of the volute, furthest from the blower wheel attachment to the hybrid power plant, collects the airflow into an enclosed duct 1018. This duct 1018 is then arranged to feed the high pressure cooling airflow to two aluminum heat exchangers in a V-configuration. One of these coolers may be for the engine oil, while the other may be for the engine intake air.

[0121] Section B of the volute between sections A and C (e.g., the center section) collects the airflow into two ducts diametrically opposed, 180 degrees apart. These two ducts are positioned to provide cooling airflow to the piston engine cylinder. Section C of the volute, closest to where the fan blades 1020 are attached to the hybrid power plant, is the section dedicated to cooling the electric motor and inverter. This airflow is contained within the shroud 1014 and may be forced to flow in parallel through the shroud 1014. The shroud 1014 may include machined aluminum fins therein connected to the electric motor and / or inverter housing to allow for cooling airflow and heat transfer from the electric motor and / or inverter housing to the cooling flow.

[0122] Various embodiments may include multiple centrifugal or radial blower wheels and / or multiple axial fan blades, which may rotate at different RPM if a gearbox is used. These blowers or fans may be connected to one or more ducts that feed air to multiple dedicated radiators (e.g., fluid-to-air heat exchangers or air-to-air heat exchangers), or may be directly connected to components designed to be cooled by airflow (such as our cylinders and our motors / generators).

[0123] In various embodiments, a single rotating shaft may be used with two centrifugal blower elements connected back to back to each other and both attached to the shaft as described herein. In such an embodiment, one side of the hub may drive a larger blower that meets multiple cooling requirements with relatively high pressure rise and high mass flow rates. The other side of the hub may drive a smaller blower of the same or different radius to provide different levels of pressure rise and mass flow rates.

[0124] In various embodiments, a device including one or more centrifugal blowers and / or one or more axial fan blade sets may be mechanically driven from the crankshaft and / or power shaft of the hybrid power plant, which can achieve different packaging requirements / footprints of the system and / or can be used to provide different airflows having different pressure rise, mass flow rates, or other engineering parameters as desired for a particular aircraft and its respective propulsion system and cooling needs.

[0125] In various embodiments, the mechanical drive system may include gearing or another type of transmission (e.g., belt, continuously variable transmission (CVT), fluid torque converter) to vary the RPM of the fan system relative to the RPM of the crankshaft or power shaft, rather than rotating at only a single RPM. Such a feature achieves all of the benefits described above by avoiding an electrically driven cooling system, and the gearing adds flexibility to the design of the aerodynamic fan / blower.

[0126] In various embodiments, the ductwork of such a system may be made from various components such as aluminum, composites, three-dimensional (3D) printed materials, etc., or any combination thereof, to achieve a lightweight system. The ductwork material may also be molded into complex curved surfaces, providing aerodynamic efficiency, etc. Composite materials such as carbon fiber and epoxy may be used to achieve weight savings compared to materials such as aluminum or other metals. The ducts themselves (e.g., between a shaft-driven blower or fan and the device requiring cooling) are also carefully designed to help balance the pressure drop and air mass flow rate to the multiple devices relative to the generator. This may include the shape and size of the duct, constrictions along straight or simple duct sections for engineering purposes.

[0127] In various embodiments, a thermostatic control may also be added to prevent overcooling (e.g., when the ambient air temperature is low). Various embodiments may also include active dampers in the ducts to vary the ratio of air flowing through each duct (e.g., to each component being cooled). The temperature of the component being cooled is also monitored by the controller, and if the component becomes too hot, the controller can adjust the air flow to that component to provide a greater volume and / or pressure of cooling air.

[0128] 13 shows a schematic diagram of a second example cooling system for a hybrid power plant according to an exemplary embodiment. A blower 600 takes in air and supplies it to a charge air cooler (e.g., an engine intercooler) where it is sent through duct 602 to an engine 606 to cool the engine's cylinders. Other air can pass through duct 608 to an engine oil cooler 610.

[0129] 14 shows a schematic diagram of a third example of a cooling system for a hybrid power plant according to an exemplary embodiment. A blower 600 can supply air to a charge air cooler 602, which can separately supply air to a duct 604 to cool the cylinders of an engine 606. Other air can pass through a duct 608 to an engine oil cooler 610.

[0130] Figure 15 illustrates a schematic diagram of a fourth example cooling system for a hybrid power plant in accordance with an exemplary embodiment. Figure 15 is similar to Figure 13, in that, for example, air is also provided from blower 600 to motor 612 (e.g., an electric machine or motor / generator as described herein).

[0131] 16 illustrates a schematic diagram of a fifth example cooling system for a hybrid power plant in accordance with an exemplary embodiment. FIG 16 is similar to FIG 15, except that additional air is supplied to the liquid air cooler via duct 614 to cool the motor / generator and / or other power electronics.

[0132] FIG. 17 illustrates a top view of an example hybrid power plant with a cooling system according to an exemplary embodiment. FIG. 18 illustrates a cross-sectional view of the example hybrid power plant of FIG. 17 along line AA according to an exemplary embodiment. FIG. 19 illustrates a cross-sectional view of the example hybrid power plant of FIG. 17 along line BB according to an exemplary embodiment. FIG. 20 illustrates an alternative view of the example hybrid power plant of FIG. 17 according to an exemplary embodiment, showing details of the engine cooling fins. FIG. 21 illustrates a side view of the example hybrid power plant of FIG. 17 with a cooling system according to an exemplary embodiment.

[0133] In particular, Figures 17-21 show the engine 102 with shaft 110 powering the fan wheel 302, bringing air through the blower inlet 120. The air passes through the upper volute 116, the lower volute 118, the right duct 202, and the left duct 204. The fan wheel 302 may be surrounded by a charge air cooler 108, which receives heated charge air from the turbocharger 153 inlet via duct 112 and outputs cooled charge air via duct 114 to the engine 102, cooled by air provided by the rotation of the fan wheel 302. Figure 19 further shows the engine intake filter 306 and the engine exhaust 308. Figure 19 also shows the fan wheel fins 304 of the fan wheel 302.

[0134] The motor / generator mount 122 also mounts the motor-generator 106 to the engine 102. The right duct 202 and the left duct 204 also feed air to the engine baffling 206 to cool the engine 102. FIG. 20 shows the engine cylinder fins 402 that are used to cool the engine with the cool air from the ducts 202 and 204. FIG. 21 further shows an engine oil cooler 502 that can receive air via the duct 202 to cool oil for the engine, where the oil is supplied to the engine via a supply line 504 and returned to the cooler via a return line 506. A duct separator 508 can also be used to separate a portion of the duct 202 so that some air is directed to the engine cylinders while other air is directed to the oil cooler 502.

[0135] In various embodiments, various aspects of the cooling system may also be controlled to ensure that the components of the flexible architecture or power plant are at or within a desired temperature range. The ambient environment temperature and / or the temperature at various locations in the cooling system may be sensed and used to control various aspects of the cooling system. Temperature sensors may be located on, in, or near any of the components of the cooling system or flexible architecture described herein. Additionally, temperature sensors may be located on, in, or near the enclosure of the cooling system and flexible architecture, for example. These temperature sensors may be used to measure the actual or approximate temperatures of the various components, as well as the ambient air temperature inside or outside the enclosure. By way of example only, the cylinders of a piston engine may be air-cooled by the cooling system described herein. For example, if the environment (e.g., ambient temperature) is cold, the outside of the cylinder may become too cold due to significant air cooling, while heat from combustion inside the cylinder may cause the piston to expand (and conversely the cylinder may contract due to significant air cooling). Thus, to avoid seizing of the engine's pistons and cylinder bores due to temperature differentials, the cooling system may be controlled to limit the amount of air used to cool the engine's cylinders. As such, various embodiments may include one or more throttles, valves, and / or restrictors to prevent some or all of the airflow from the cooling system from being used to cool aspects of the power plant, here the engine's cylinders. The throttles, valves, and / or restrictors may be located within various duct structures of the cooling system, as described herein, or otherwise within the fluid path between the blower / fan and the components being cooled to restrict the flow of air.For example, the controller / processor of FIG. 2A or FIG. 2B can be used to send electrical control signals to control throttles or valves, thereby restricting airflow to a particular component as needed (by turning off airflow through the component's ducts completely, or restricting airflow somewhere between fully open and fully closed). Thus, control, such as closed loop control, can be achieved to control how much airflow and cooling reaches a particular component of the power plant. Various types of throttles, valves, and / or restrictors, such as controllable butterfly throttles, slide throttles, barrel throttles, etc., may be used. Control can also be manual, based on season or average temperature of the environment, etc. For example, semi-permanently installed restrictor disks with various size openings can be attached to and swapped out of the ducts to control how much airflow reaches a particular component based on season, geography, etc. (all of which can affect average temperature).

[0136] 22 is a flow chart illustrating an example method 2200 for controlling a cooling system according to an example embodiment. At 2202, temperature information is received at a controller or processor from a temperature sensor located on, within, or near a component of the power plant desired to be cooled. At 2204, ambient temperature information is received at the processor or controller from a temperature sensor, for example, in, on, or near an enclosure in which the flexible architecture is enclosed.

[0137] In operation 2206, the processor or controller determines a desired level of cooling for the power plant components based on at least one of a temperature associated with the power plant components or an ambient temperature. Based on that determination, in 2208, the processor may output a signal to an electrically controlled throttle or valve mechanism (or other component of the cooling system that can control or restrict airflow) to control the level of cooling provided to the power plant components. For example, instead of or in addition to using a throttle or valve mechanism to control airflow to a particular component of the power plant, the processor or controller may also control aspects of the cooling system that affect how much airflow is actually generated by a fan, impeller, or blower of the cooling system. For example, a control signal may be sent to a gearbox attached to the fan, impeller, or blower such that a different gear ratio is used between the shafts powering the fan, impeller, or blower, causing the fan, impeller, or blower to rotate at a different RPM, thereby controlling the airflow of the cooling system.

[0138] 28A-28C illustrate a portion of a cooling system including a cross-section of the ductwork of the cooling system according to an exemplary embodiment. FIG. 29A and FIG. 29B illustrate additional portions of the cooling system including additional details of the ductwork of the cooling system according to an exemplary embodiment. In particular, FIG. 28A-28C and FIG. 29A and FIG. 29B illustrate examples of dimensions and / or possible ratios of the ductwork of an exemplary cooling system. Various specific sizes of components are described below, however, these sizes are not limiting and other sizes outside of these ranges or values ​​may be used. For example, if the cooling system is designed for a turbocharged 5.0 liter diesel compression ignition piston combustion engine using a flat-four configuration, oil-cooled cylinder head, and air-cooled cylinder jugs, the following sizes may be used:

[0139] FIG. 28A shows a diagram 2800 showing a cross section c of two ducts leading to the engine's cooling air cylinder. Each of the two ducts has an internal area of ​​9.62 in 2 through which air flows. 2) In various embodiments, the area of ​​each of the ducts may be anywhere from 6 to 15 square inches, including 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5, 11, 11.5, 12, 12.5, 13, 13.5, 14, 14.5, or 15 square inches. FIG. 28B shows a diagram 2810 illustrating the diameter a of the fan wheel, which in one example may be, for example, 18.75 inches (in). In various embodiments, the diameter of the fan can be anywhere from 12 to 25 inches, such as 12 inches, 13 inches, 14 inches, 15 inches, 16 inches, 17 inches, 18 inches, 19 inches, 20 inches, 21 inches, 22 inches, 23 inches, 24 inches, 25 inches, etc. FIG. 28B further illustrates dimensions d and e, where d is the axial length of the fan, impeller, or blower that directs air to one or more heat exchangers of the flexible architecture, and e is the axial length of the fan, impeller, or blower that directs air toward the air-cooled cylinder (e.g., through duct c shown in FIG. 28A). Various ratios of air can be used to direct air to various components of the flexible architecture. In the example of FIG. 28B, 60% of the axial length d is associated with the heat exchanger (so that approximately 60% of the air moved by the fan, impeller, or blower is directed to the heat exchanger of the system), while 40% of the moved air is directed to cylinder cooling. In different embodiments, different percentages are possible, such as 20-80% of the air being directed to the heat exchanger and 20-80% of the air being directed to cylinder cooling. In various embodiments, different splits are possible, such as 20 / 80, 25 / 75, 30 / 70, 35 / 65, 40 / 60, 45 / 55, 50 / 50, 55 / 45, 60 / 40, 65 / 35, 70 / 30, 75 / 25, or 80 / 20. FIG. 28C shows a diagram 2820 in which a cross section b of a duct directing air towards one or more heat exchangers is shown. Duct b has an internal airflow area of ​​15.8 square inches (in 2In various embodiments, the area of ​​each of the ducts may be 8 square inches, 8.5 square inches, 9 square inches, 9.5 square inches, 10 square inches, 10.5 square inches, 11 square inches, 11.5 square inches, 12 square inches, 12.5 square inches, 13 square inches, 13.5 square inches, 14 square inches, 14.5 square inches, 15 square inches, 15.5 square inches, 16 square inches, or more. The size may be anywhere from 8 to 24 square inches, including 16.5 square inches, 17 square inches, 17.5 square inches, 18 square inches, 18.5 square inches, 19 square inches, 19.5 square inches, 20 square inches, 20.5 square inches, 21 square inches, 21.5 square inches, 22 square inches, 22.5 square inches, 23 square inches, 23.5 square inches, or 24 square inches.

[0140] FIG. 29A shows a side view 2900 of a duct around a fan, impeller, or blower and example dimensions. FIG. 29B shows a side view 2910 of a duct around a fan, impeller, or blower and example dimensions. In FIG. 29A, dimensions associated with a duct that directs air to one or more heat exchangers are shown. In FIG. 29B, dimensions associated with a duct that directs air to a cylinder of an engine are shown. Another duct similar to the dimensions in FIG. 29B may also be included on the opposite side of the fan, impeller, or blower as described herein. The dimensions shown in FIG. 29A and FIG. 29B are in inches relative to the axis of the fan, impeller, or blower. While FIG. 29A and FIG. 29B show example dimensions, other dimensions may be used in various embodiments. For example, each dimension shown may vary within a range of plus or minus 6 inches, 5.5 inches, 5 inches, 4.5 inches, 4 inches, 3.5 inches, 3 inches, 2.5 inches, 2 inches, 1.5 inches, 1 inch, or 0.5 inches of the indicated dimension.

[0141] FIG. 30 is a diagram of an example of a computing environment including a general-purpose computing system environment 100, such as a desktop computer, laptop, smartphone, tablet, or other similar device capable of executing instructions, such instructions being stored in a non-transitory computer-readable medium. The various computing devices disclosed herein (e.g., processor / controller 205, aircraft main controller 220, processor / controller 280, or any other computing device in communication with these controllers, which may be part of other components or control systems of the aircraft, whether onboard the aircraft or remote from the aircraft) may be similar to computing system 100 or may include some components of computing system 100. Also, while described and illustrated in the context of a single computing system 100, those skilled in the art will appreciate that the various tasks described below may also be performed in a distributed environment having multiple computing systems 100 linked via a local or wide area network, in which the executable instructions may be associated with and / or executed by one or more of the multiple computing systems 100.

[0142] In its most basic configuration, the computing system environment 100 typically includes at least one processing unit 102 and at least one memory 104, which may be linked via a bus 106. Depending on the exact configuration and type of computing system environment, the memory 104 may be volatile (such as RAM 110), non-volatile (such as ROM 108, flash memory, etc.), or a combination of the two. The computing system environment 100 may have additional features and / or functionality. For example, the computing system environment 100 may also include additional storage devices (removable and / or non-removable), including, but not limited to, magnetic or optical disks, tape drives, and / or flash drives. Such additional memory devices may be made accessible to the computing system environment 100, for example, by a hard disk drive interface 112, a magnetic disk drive interface 114, and / or an optical disk drive interface 116. As will be appreciated, each of these devices are linked to the system bus 306 and enable reading and writing to the hard disk 118, the removable magnetic disk 120, and / or the removable optical disk 122, such as a CD / DVD ROM or other optical media. The drive interfaces and their associated computer readable media enable non-volatile storage of computer readable instructions, data structures, program modules, and other data for the computing system environment 100. Moreover, those skilled in the art will appreciate that other types of computer readable media capable of storing data can be used for this same purpose. Examples of such media devices include, but are not limited to, magnetic cassettes, flash memory cards, digital video disks, Bernoulli cartridges, random access memory, nano drives, memory sticks, other read / write and / or read only memory, and / or other methods or techniques for storing information, such as computer readable instructions, data structures, program modules, or other data. Any such computer storage media may be part of the computing system environment 100.

[0143] A number of program modules may be stored in one or more memory / media devices. For example, a basic input / output system (BIOS) 124, containing the basic routines that help to transfer information between elements within the computing system environment 100, such as during start-up, may be stored in ROM 108. Similarly, the RAM 110, the hard drive 118, and / or the peripheral memory devices may be used to store computer-executable instructions including an operating system 126, one or more application programs 128 (which may include functionality disclosed herein, for example), other program modules 130, and / or program data 122. Additionally, computer-executable instructions may be downloaded into the computing environment 100, as needed, for example, via a network connection.

[0144] An end user may enter commands and information into the computing system environment 100 through input devices such as a keyboard 134 and / or a pointing device 136. Other input devices, not shown, may include a microphone, joystick, game pad, scanner, etc. These and other input devices are typically connected to the processing unit 102 by a peripheral interface 138 coupled to the bus 106. The input devices may be connected directly or indirectly to the processor 102 through an interface, such as, for example, a parallel port, a game port, Firewire, or a universal serial bus (USB). For viewing information from the computing system environment 100, a monitor 140 or other type of display device may be connected to the bus 106 through an interface, such as a video adapter 132. In addition to the monitor 140, the computing system environment 100 may also include other peripheral output devices, not shown, such as speakers and a printer.

[0145] The computing system environment 100 may also utilize logical connections to one or more computing system environments. Communications between the computing system environment 100 and a remote computing system environment may be exchanged through an additional processing device, such as a network router 152 responsible for network routing. Communications with the network router 152 may be performed through a network interface component 154. Thus, it will be understood that within such a network environment, for example the Internet, the World Wide Web, a LAN, or other similar types of wired or wireless networks, program modules depicted relative to the computing system environment 100, or portions thereof, may be stored in the memory storage devices of the computing system environment 100.

[0146] The computing system environment 100 may also include location determination hardware 186 for determining a location of the computing system environment 100. In some cases, the location determination hardware 156 may include, for example, a GPS antenna, an RFID chip or reader, a WiFi antenna, or other computing hardware that may be used to capture or transmit signals that may be used to determine the location of the computing system environment 100.

[0147] Although the present disclosure has described specific embodiments, it will be understood that the claims are not intended to be limited to these embodiments unless expressly set forth in the claims. On the contrary, the present disclosure is intended to cover alternatives, modifications, and equivalents that may be included within the spirit and scope of the present disclosure. Furthermore, in the detailed description of the present disclosure, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. However, it will be apparent to one skilled in the art that systems and methods consistent with the present disclosure may be practiced without these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to unnecessarily obscure various aspects of the present disclosure.

[0148] Some portions of the detailed description of this disclosure are presented in terms of procedures, logic blocks, processes, and other symbolic representations of operations on data bits within a computer or digital system memory. These descriptions and representations are the means used by those skilled in the data processing arts to most effectively convey the substance of their work to others skilled in the art. A procedure, logic block, process, or the like, is here, and generally, conceived to be a self-consistent sequence of steps or instructions leading to a desired result. These steps are those requiring physical manipulations of physical quantities. Usually, though not necessarily, these physical manipulations take the form of electrical or magnetic data capable of being stored, transferred, combined, compared, and otherwise manipulated in a computer system or similar electronic computing device. For reasons of convenience and with reference to common usage, such data will be referred to as bits, values, elements, symbols, characters, terms, numbers, or the like in connection with the various presently disclosed embodiments.

[0149] However, it should be noted that these terms should be interpreted as referring to physical operations and quantities, and are merely convenient labels that should be further interpreted in light of the terms commonly used in the art. Unless otherwise indicated, and as will be apparent from the discussion herein, throughout the discussion of the present embodiments, discussions utilizing terms such as "determine", or "output", or "transmit", or "record", or "locate", or "store", or "display", or "receive", or "recognize", or "utilize", or "generate", or "provide", or "access", or "confirm", or "notify", or "deliver" are understood to refer to the operations and processes of a computer system or similar electronic computing device that manipulates and transforms data. Data is represented as physical (electronic) quantities in the registers and memory of the computer system, and is transformed into other data that are also represented as physical quantities in the memory or registers of the computer system, or other such information storage, transmission, or display devices described herein or otherwise understood by those skilled in the art.

[0150] In an exemplary embodiment, any of the operations described herein may be implemented at least in part as computer readable instructions stored on a computer readable medium or in a memory that, when executed by a processor, can cause a computing device to perform an operation.

[0151] The foregoing description of the exemplary embodiments has been presented for purposes of illustration and description. It is not intended to be exhaustive or to be limited to the precise form disclosed, and modifications and variations may be possible in light of the above teachings or from practice of the disclosed embodiments. It is intended that the scope of the invention be defined by the appended claims and their equivalents.

Claims

1. 1. An aerospace hybrid powertrain system, comprising: The engine, A power shaft; an electric machine having the power shaft therein or passing therethrough, the electric machine being configured to output electrical power used to propel the aircraft; a fan, impeller, or blower connected to the power shaft; The fan, impeller, or blower may be configured to blow air through the a component of at least one of the engine or the electric machine; or a cooling element including at least one of a heat exchanger or a finned heat sink configured to cool the components of at least one of the engine or the electric machine; Aerospace hybrid powertrain system.

2. the electric machine is configured to receive electrical power from an electrical energy storage device via an electrical input / output to drive the power shaft; the electric machine is configured to output electrical power to an electric motor and / or the electrical energy storage device via an electrical input / output upon rotation of the power shaft by the engine; The aerospace hybrid powertrain system of claim 1 , wherein the electric machine is cooled by the cooling element as a result of the air being directed by the fan, impeller, or blower.

3. 3. The aerospace hybrid powertrain system of claim 2, wherein the electric machine is configured to convert between 50 and 100 percent of the energy provided by the power shaft while the engine is driving the power shaft into electrical output power.

4. 2. The aerospace hybrid powertrain system of claim 1, wherein the engine includes an air-cooled cylinder that is cooled as a result of the air being directed by the fan, impeller, or blower.

5. 10. The aerospace hybrid powertrain system of claim 1, wherein the engine uses a liquid fuel including any of diesel fuel, Jet A fuel, gasoline, hydrogen, biofuel, and synthetic fuel alternatives.

6. The fan, impeller, or blower may be directly coupled to the power shaft such that the fan, impeller, or blower is directly driven by the power shaft; or 10. The aerospace hybrid powertrain system of claim 1, indirectly coupled to the power shaft via a gearbox, pulley, or torque converter.

7. 2. The aerospace hybrid powertrain system of claim 1, wherein the fan, impeller, or blower is a first fan, impeller, or blower, and the system further includes a second fan, impeller, or blower connected to the power shaft.

8. 2. The aerospace hybrid powertrain system of claim 1, further comprising at least two air ducts configured to receive air from the fan, impeller, or blower and direct the air for cooling the components of at least one of the engine or the electric machine.

9. A first duct of the at least two air ducts directing air to cool the cylinders of said engine; directing air into an engine oil cooler of said engine; or 10. The aerospace hybrid powertrain system of claim 8, configured to at least one of: direct air to an engine intercooler or a charge air cooler.

10. 9. The aerospace hybrid powertrain system of claim 8, wherein a first of the at least two air ducts is a shroud and is configured to direct air for cooling the electric machine or an associated component thereof.

11. 2. The aerospace hybrid powertrain system of claim 1, wherein the engine is a piston engine, a rotary engine, a turboshaft engine, a turboprop engine, a turbofan engine, or a turbojet engine.

12. further comprising power electronics for converting an alternating current (AC) output of the electric machine to a direct current (DC); 10. The aerospace hybrid powertrain system of claim 1, wherein the DC power on the DC bus is configured to power a propulsion component of an aircraft.

13. 1. A method for controlling cooling of an aerospace hybrid powertrain system, the method comprising: receiving, by a processor of a computing device, data indicative of at least one of a temperature associated with a component of the aerospace hybrid powertrain system or an ambient or environmental temperature; the processor determining a desired level of cooling for the component based on the temperature associated with the component of the aerospace hybrid powertrain system or the ambient or environmental temperature; and outputting a control signal configured to change a state of an airflow control device to regulate airflow to components of the aerospace hybrid powertrain system based on the determination of the desired cooling level. method.

14. The aerospace hybrid powertrain system comprises: The engine, A power shaft; an electric machine having the power shaft therein or passing therethrough, the electric machine being configured to output electrical power configured to be used to propel the aircraft; a fan, impeller, or blower connected to a fan, impeller, or blower shaft; The fan, impeller, or blower may move air through a component of at least one of the engine or the electric machine; or a cooling element including at least one of a heat exchanger or a finned heat sink configured to cool a component of at least one of the engine or the electric machine; The fan, impeller, or blower shaft is supplied with mechanical power from the power shaft. The method of claim 13.

15. The method of claim 14, wherein the power shaft and the fan, impeller, or blower shaft are connected by a gearbox, pulley, or torque converter, allowing the fan, impeller, or blower shaft to rotate at a different revolutions per minute (RPM) than the power shaft.

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