Airflow path and / or packaging for an aircraft hybrid powerplant

Abstract

An aerospace hybrid powerplant includes a nacelle and a bypass fan configured to generate thrust by directing airflow along a bypass air path within the nacelle. The aerospace hybrid powerplant further includes an engine configured to output mechanical power to the bypass fan. The aerospace hybrid powerplant further includes at least one electric machine configured to output electrical power or output mechanical power to the bypass fan. The engine is positioned within the nacelle and out of the bypass air path and the at least one electric machine is positioned within the nacelle and out of the bypass air path.

Description

AIRFLOW PATH AND / OR PACKAGING FOR AN AIRCRAFT HYBRIDPOWERPLANTCROSS-REFERENCE TO RELATED PATENT APPLICATION

[0001] This application claims the benefit of U. S. Provisional Patent Application No. 63 / 665,009, filed June 27, 2024, the entire contents of each of which is hereby incorporated by reference.BACKGROUND

[0002] There are varying types of aircraft that are propelled using different types of propulsion mechanisms, such as propellers, turbine or jet engines, rockets, or ramjets. Different types of propulsion mechanisms may be powered in different ways. For example, some propulsion mechanisms like a propeller may be powered by an internal combustion engine or an electric motor. In some aircraft, a combination of propulsion mechanisms and methods may be used to provide power to propulsion mechanisms, such as a hybrid powerplants having mechanical and electrical components / outputs.SUMMARY

[0003] In an embodiment, an aerospace hybrid powerplant includes a nacelle and a bypass fan configured to generate thrust by directing airflow along a bypass air path within the nacelle. The aerospace hybrid powerplant further includes an engine configured to output mechanical power to the bypass fan. The aerospace hybrid powerplant further includes at least one electric machine configured to output electrical power or output mechanical power to the bypass fan. The engine is positioned within the nacelle and out of the bypass air path and the at least one electric machine is positioned within the nacelle and out of the bypass air path.

[0004] In an embodiment, an aerospace hybrid powerplant includes a nacelle and a bypass fan configured to generate thrust by directing airflow along a bypass air path within the nacelle. The aerospace hybrid powerplant further includes an engine configured to output mechanical power to the bypass fan. The aerospace hybrid powerplant further includes at least one electric machine configured to output electrical power or output mechanical power to the bypass fan. The aerospace hybrid powerplant-1- ACTIVE 712259322v2further includes at least one inverter electrically coupled to the at least one electric machine. The engine is positioned within the nacelle and out of the bypass air path and the at least one electric machine is positioned within the nacelle and out of the bypass air path.

[0005] In an embodiment, an aerospace hybrid powerplant includes a nacelle and a bypass fan configured to generate thrust by directing airflow along a bypass air path within the nacelle. The aerospace hybrid powerplant further includes an engine configured to output mechanical power to the bypass fan. The aerospace hybrid powerplant further includes a plurality of inverters. The aerospace hybrid powerplant further includes a plurality of electric machines each configured to receive mechanical power from the engine and output electrical power to an inverter of the plurality of inverters. The plurality of electric machines are further each configured to receive electrical power through the inverter and output mechanical power to the bypass fan. The aerospace hybrid powerplant further includes a power blend gearset configured to output a blend of mechanical power to the bypass fan from the engine and the plurality of electric machines. Each of the plurality of inverters, the plurality of electric machines, and the power blend gearset is positioned within the nacelle and out of the bypass air path.

[0006] A better appreciation of the objects, advantages, features, properties, and relationships of the subject matter disclosed herein will be obtained from the following detailed description and accompanying drawings which set forth illustrative examples which are indicative of the various ways in which the principles of the described embodiments may be employed.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The foregoing summary, as well as the following detailed description of exemplary embodiments, is better understood when read in conjunction with the accompanying drawings, which are included by way of example, and not by way of limitation with regard to the claimed invention.

[0008] Fig. 1 illustrates an example aerospace hybrid powerplant with a majority of the aerospace hybrid powerplant within a nacelle in accordance with an illustrative embodiment.-2- ACTIVE 712259322v2

[0009] Fig. 2 illustrates an example aerospace hybrid powerplant where less than a majority of the aerospace hybrid powerplant is within a nacelle in accordance with an illustrative embodiment.

[0010] Fig. 3 illustrates an example aerospace hybrid powerplant with an entirety of the aerospace hybrid powerplant within a nacelle in accordance with an illustrative embodiment.

[0011] Fig. 4 illustrates an example irregular bypass air path in accordance with an illustrative embodiment.DETAILED DESCRIPTION

[0012] The following description of example methods and apparatus is not intended to limit the scope of the description to the precise form or forms detailed herein. Instead the following description is intended to be illustrative so that others may follow its teachings.

[0013] Various embodiments herein relate to the design and packaging of a hybrid powerplant for aircraft, including optimizing the airflow' path and arrangement of hybrid components within a turbofan engine nacelle to minimize aerodynamic drag and maximize efficiency. The hybrid powerplant integrates both mechanical and electrical power outputs, allowing for flexible distribution of engine power between thrust generation (e.g., via a bypass fan) and electrical power generation.

[0014] Optimized or enhanced component packaging for hybrid propulsion components such as electric motors / generators, inverters, gearboxes, and associated support elements may include arranging the components within a defined clearance diameter inside an engine nacelle and / or duct (e.g., a turbofan duct). In other words, the components may be packaged together inside an engine nacelle and / or duct (e.g., a turbofan duct) to be within a particular predetermined distance or radius from an axis of the engine nacelle and / or duct (e.g., a turbofan duct). This packaging may minimize obstructions in the bypass airflow path of a turbofan engine, reducing internal drag and improving thrust and overall aircraft efficiency. Such a design may allow for high-speed airflow from the bypass fan to pass through the nacelle ’ith minimal disturbance, allowing for efficient thrust production and reduced drag.

[0015] The hybrid powerplants described herein also provide for flexible power distribution, for example with a controllable transmission system that can direct a-3- ACTIVE 712259322v2majority of, substantially all of, or all of the engine's output to either mechanical (thrust) or electrical (power generation) outputs, or a combination thereof, depending on operational needs.

[0016] Various embodiments may also be selected using an iterative sizing process. For example, a bypass fan's outer and inner diameters may be selected based on a target thrust, aircraft drag, and / or available power, with a clearance diameter iteratively adjusted or selected to ensure all hybrid components fit without compromising performance.

[0017] Modular arrangements may also be used in various embodiments. For example, multiple smaller motors / generators may be arranged in various geometric patterns (e.g., planar, cylindrical, and / or gatling gun style) within the clearance diameter to optimize space, efficiency, and power output. Examples of systems that use multiple motor / generators further include those described in U. S. Pat. Appln. No. 18 / 927,784, filed on October 25, 2024, the entire contents of which is hereby incorporated by reference.

[0018] The various embodiments herein may also benefit with respect to reducing electromagnetic interference. For example, placing inverters close to the motors / generators inside the nacelle of a system may reduce electromagnetic interference and system weight. A clearance diameter and component arrangement can also vary along the nacelle's length and cross-section, accommodating different engine architectures and power levels. The cross-section itself may also vary as desired to provide a desired architecture and / or bypass airflow path.

[0019] The embodiments herein also encompass methods and computer-readable instructions for controlling and using the hybrid powerplants described herein, including the management of power splitting and component operation. Overall, the embodiments herein provide a highly integrated, aerodynamically efficient hybrid powerplant architecture for aircraft, enabling improved performance, reduced drag, and / or flexible power management.

[0020] As such, the advantageous motor / generator and inverter packaging as described herein may include arranging all hybrid propulsion units to fit within the shadow of the spinner or bypass fan, inside a duct, nacelle, or other housing while preserving a bypass airflow path of a turbofan engine, for example. An embodiment-4- ACTIVE 712259322v2may include 2 motor / generators one direction and 1 motor / generator the other direction in gatling gun arrangement. Motor / generators may also be referred to herein as emachines. In various embodiments other numbers of emachines and other arrangements of those emachines may be used. For example, the emachines may be organized to have a planar spacing.

[0021] By managing airflow that starts at a fan disc surface of a turbine engine or turbofan engine of a hybrid powerplant and packaging hybrid powerplant components within a center of a nacelle or duct, that air being moved by a fan disc surface or bypass fan may advantageously get out of the nacelle, duct, or other component as thrust without getting disturbed and reducing performance levels of the system.

[0022] A measure of aircraft performance is coefficient of drag. Aircraft spend much of their time in forward flight at high speed, and drag is overcome by power. Drag is related to, among many other factors, certain size attributes of an aircraft such as the size of the fuselage, the thickness of the wing, or the diameter of the engines. Everything else being equal, an aircraft with a smaller engine producing the same thrust as a larger engine will be more efficient.

[0023] Furthermore, the same drag principles and the same measure of efficiency are a consideration inside of a turbofan engine. Inside of a turbofan engine nacelle or turbofan duct, air passes along a bypass air path starting at an inlet, through the fan, around any other obstructions, and then exiting in a ring pattern as jet thrust.Minimizing obstructions in the bypass air path as described herein therefore advantageously minimizes drag and optimizes efficiency.

[0024] The elements of a hybrid powerplant featuring blended turbofan operation (e.g., a maximum available range of output shared between electrical power and shaft power driving a fan) may include any combination of electric motors (emachines), gearboxes, cooling, electrical, and / or electronic components. Arrangement of these elements in such a manner that might block or restrict the high-speed airflow of the engine bypass air path could result in low efficiency, low thrust, and limited value. Arrangement of those elements outside of the bypass air path (such as outside the nacelle of a turbofan engine) may result in high weight, low efficiency, and / or other mechanical limitations such as instability caused by vibrations.-5- ACTIVE 712259322v2

[0025] Described herein are various embodiments for packaging some or all elements of a hybrid powerplant featuring blended turbofan functionality in a manner which minimizes aerodynamic drag of the entire aircraft and drag in the bypass air path through the turbofan engine.

[0026] Aerodynamic drag of the entire aircraft may be minimized by utilizing the smallest possible outside diameter for the fan or a generally small outside diameter for the fan that still achieves the power output desired for the system. Such a fan’s diameter may be influenced by target RPM of the fan, thrust, and by the balance between static thrust valuable for takeoff and dynamic or high-speed thrust such as during forward flight. A blended turbofan powerplant, because it can produce massive electrical power such as for vertical takeoff, may reduce the benefit of a large fan disk such as might be chosen for efficient production of static thrust needed for conventional runway takeoff. Since the aircraft is not conducting takeoff starting at low or zero velocity using a runway, static thrust may have less value. Shifting the balance in bypass fan performance toward dynamic thrust and away from static thrust may enable a smaller fan outer diameter and lower overall aircraft drag than would otherwise be used for a conventional takeoff and landing aircraft.

[0027] Within the bypass air path, inside the nacelle or ducts of a blended turbofan hybrid engine, there may be somewhat limited cross-sectional area to package all of the necessary components such as emachines, gearboxes, electrical, and electronic hardware. Therefore, described herein are embodiments for optimizing power output, flexibility of power conversion, and for packaging some or all of an entire hybrid system inside an engine nacelle or duct chosen for lowest aircraft drag (small outside diameter (OD)) with maximum efficiency (e.g., having suitable bypass air path remaining inside in the nacelle).

[0028] Various embodiments herein therefore advantageously provide for improved combinations of engine nacelle OD (relates to aircraft drag), engine thrust, and engine efficiency (relates to internal drag due to obstructions). Blended turbofan components packaged inside nacelle may further allow for a full-flying configuration (under wing or on outside of fuselage). If components were packaged externally to the nacelle of a turbofan engine for example, it may lead to massive vehicle drag or packaging of-6- ACTIVE 712259322v2various hybrid engine components inside the fuselage and therefore shielded from the high-speed airstream.

[0029] Embodiments of the systems and methods described herein may therefore include a nacelle-mounted hybrid powerplant featuring external airflow (e.g., mounted under the wing or on the side of the fuselage), and may also include embodiments for internal duct performance by minimizing obstructions even for a fuselage mounted engine package with parts outside the air stream.

[0030] Various embodiments include aspects of a hybrid powerplant packaged in an efficient way. For example, an aircraft powerplant may include an engine having an output power shaft. Hie aircraft powerplant may further include a pow’er transmission coupled to the output power shaft of the engine. The power transmission is configured to divide power output of the engine between a mechanical power output and an electrical power output. A majority of, substantially all of, or all of the power output from the engine is adjustable to output to either of the mechanical power output or the electrical power output. The aircraft powerplant further includes a propulsion mechanism (e.g., bypass fan) coupled to the mechanical power output. The aircraft powerplant further includes a control system configured to cause the power transmission to deliver the majority of, substantially all of, or all of the power output of the engine to the propulsion mechanism to generate thrust or deliver the majority of the power output of the engine as electrical power output via the electrical power output as desired (or deliver a combination of electrical and mechanical power output).

[0031] In an embodiment, a method for splitting power output from an engine of an aircraft between an electric power output and a mechanical pow’er output includes controlling, in a first mode of operation, a power transmission of the aircraft to generate electrical power using substantially all power output from the engine. The method further includes controlling, in a second mode of operation, the power transmission to generate very little or no electricity from the mechanical power output from the engine, where the second mode further comprises controlling the power transmission such that most or all of the power output from the engine is directed to the mechanical power output.

[0032] In an embodiment, an aircraft powerplant includes an engine w'ith an output power shaft configured to output power from the engine. The aircraft powerplant-7- ACTIVE 712259322v2further includes a bypass fan, an electric machine, and a transmission. The transmission includes an input, a first output shaft, and a second output shaft. The output power shaft from the engine is configured to drive the input of the transmission. The first output shaft is coupled to the bypass fan. The second output shaft is coupled to the electric machine. The transmission is controllable to vary a percentage of the power from the engine between the first output shaft and the second output shaft such that a majority of the power is selectively provided to either the first output shaft or the second output shaft.

[0033] In an embodiment, an aircraft powerplant includes an engine having a shaft. The shaft is configured to output power from the engine. The hybrid aircraft powerplant further includes a bypass fan, a first electric machine, a second electric machine, and a gearset. The gearset includes a sun gear, a plurality of planet gears connected to a planet carrier, and a ring gear. The shaft is configured to drive an input of the first electric machine and drive the sun gear. The second electric machine is configured to drive the ring gear. The bypass fan is connected to the planet carrier.

[0034] In an embodiment, a method for splitting power output from an engine between a first electric machine and a bypass fan includes controlling, in a first mode of operation using a second electric machine, a gearset to direct power primarily or wholly to the first electric machine. The gearset includes a sun gear connected to an output shaft of the engine, a plurality of planet gears connected to a planet carrier, and a ring gear connected to the second electric machine. The planet carrier is connected to the bypass fan. The method further includes controlling, in a second mode of operation using the second electric machine and the engine, the gearset to direct power to a combination of the bypass fan and the first electric machine. The method further includes controlling, in a third mode of operation using the second electric machine and the engine, the gearset to direct power primarily or wholly to the bypass fan.

[0035] In an embodiment, a power transmission for an aircraft includes a shaft input configured to receive rotational power from an engine of the aircraft, a shaft output configured to output mechanical power to a propulsion mechanism of the aircraft, an electrical output configured to output electrical power, and an electric machine configured to receive the rotational power via the shaft input and selectively generate electrical power output via the electrical output. The electrical power is selectively-8- ACTIVE 712259322v2generated by the electric machine being at least a majority of the rotational power received from the engine of the aircraft via the shaft input.

[0036] In an embodiment, a power transmission for an aircraft includes a shaft input configured to receive rotational power from a turbine engine of the aircraft, a shaft output configured to output mechanical power to a propulsion mechanism of the aircraft, an electrical output configured to output electrical power to an electric motor of the aircraft, an electric machine, a control system configured to selectively cause the electric machine to generate electrical power and output the electrical power out of the electrical output to the electric motor. The electrical power is selectively generated by the electric machine being at least a majority of the rotational power received from the engine of the aircraft via the shaft input. The control system is further configured to selectively cause the amount of electrical power generated by the electric machine to be less than a majority of the rotational power received from the engine w’hile outputting the mechanical power to the propulsion mechanism of the aircraft.

[0037] In an embodiment, a method for splitting power output from an engine of an aircraft between an electric machine and a bypass fan includes receiving, via an input shaft of a power transmission, rotational power from the engine. The method further includes selectively splitting, with gearing, clutching, and / or transmission components of the power transmission, power output from the power transmission between a mechanical power output connected to a propulsion mechanism and an electrical output of the power transmission. An amount of power output at the electrical output is selectable to be a majority of the power input from the engine at the input shaft. The power output at the electrical output is generated by at least one electric machine of the power transmission.

[0038] In an embodiment, a pow’er transmission for an aircraft includes an input power shaft configured to receive power from an engine of the aircraft, a propulsion mechanism, an electric machine, an output power shaft configured to output mechanical power to the propulsion mechanism, and an electrical output configured to output electrical pow’er generated by the electric machine. The power transmission is controllable to vary a percentage of the power from the engine between electrical power being output at the electric machine and mechanical power output at the output-9- ACTIVE 712259322v2power shaft. The power transmission is controllable such that a majority of the power is selectively provided to either the output power shaft or the electric machine.

[0039] In an embodiment, a method for splitting power output from an engine between a first electric machine and a propulsion mechanism includes controlling, in a first mode of operation, the first electric machine to generate electricity using most or all mechanical power output from the engine. The first mode further includes controlling a gearset using a second electric machine such that little or none of the mechanical power output from the engine is directed to the propulsion mechanism. The method further includes controlling, in a second mode of operation using the first electric machine and the second electric machine, the first electric machine to generate electricity using a first substantial portion of the mechanical power output from the engine and the gearset to cause a second substantial portion of the mechanical power output from the engine to be output to the propulsion mechanism. The method further includes controlling, in a third mode of operation, the first electric machine to generate very little or no electricity from the mechanical power output from the engine. The third mode further includes controlling the gearset using the second electric machine such that most or all of the mechanical power output from the engine is directed to the propulsion mechanism.

[0040] In an embodiment, a method for splitting power output from an engine between an electric machine and a propulsion mechanism includes controlling, in a first mode of operation, the electric machine to generate electricity using most or all mechanical po ’er output from the engine. The first mode further includes confrolling a gearset and / or clutches such that little or none of the mechanical power output from the engine is directed to the propulsion mechanism. The method further includes controlling, in a second mode of operation, the electric machine to generate very little or no electricity from the mechanical power output from the engine. The second mode further includes controlling the gearset and / or clutches such that most or all of the mechanical power output from the engine is directed to the propulsion mechanism.

[0041] Various embodiments herein therefore provide for including all, substantially all, most, or some other combination of components of the power transmission, the electrical power generation, and the control of the electrical power generation and dividing / blending elements described herein to be packaged inside the duct or engine-10- ACTIVE 712259322v2nacelle. Furthermore the packaging may be optimized to allow maximum airflow and thrust, and to minimize internal drag.

[0042] Electrical power transmission components may include shafts, motor / generators or emachines, inverters, gearboxes and associated support elements such as bus bars, wiring, terminals / connectors, and / or thermal management equipment.

[0043] Various embodiments may also include:(1) Choosing a fan outside diameter (OD) based on a combination of factors:Target thrust curves (thrust vs. forward vehicle speed, altitude, and temperature), aircraft forward velocity and drag targets, and available RPM for the power shaft that drives the fan. Larger diameter fans may give better static and low-speed thrust, smaller diameter fans may give better high-speed performance. Fan outer diameter may also be driven by RPM – one key parameter is tip speed and keeping that at a correct margin relative to the speed of sound under expected operating conditions (e.g., it may be desirable to keep tip speed below the speed of sound in various embodiments).(2) Choosing a fan inside diameter (ID) based on the target for power consumption and target fan thrust.(3) Once the fan inside diameter is chosen, that may determine a clearance diameter or the region inside the blended turbofan that is available for the packaging of the hybrid components (e.g., the clearance diameter may intersect with an axis of the nacelle or duct such that the clearance diameter defines a region in the middle of the nacelle or duct where components may be placed without being in a bypass airflow path).

[0044] The above may also be an iterative process. A provisional fan OD may be chosen based on aircraft-level target performance parameters. Available power and target thrust then may determine the fan ID and clearance diameter. If the components of a suitable hybrid architecture cannot be packaged within the clearance diameter, then the process may start over again with new assumptions as needed to provide the minimum clearance diameter and with minimal negative impact to the overall hybrid powerplant performance metrics.

[0045] A clearance diameter may be defined herein as a region in the hybrid powerplant where the hybrid power conversion equipment is contained. The clearance-11- ACTIVE 712259322v2diameter may be out of the bypass airflow path. This power conversion equipment may include some or all of, but is not limited to, motor / generator units, inverter / motor controller units, gearing in various forms, high and low-voltage power and signal connections, plumbing of liquids for lubrication, cooling elements such as heat exchangers, management of airflow for cooling or other uses in and around the other equipment, bus bars, power wiring, communications and control wiring, or any combination thereof. A cylindrical or other shaped air path may be provided to generate thrust, where the power equipment is placed out of or not within the airflow path. This cylindrical air path may be around the outside of a clearance diameter, yet inside a turbofan duct, such as depicted in Fig. 4.

[0046] For a turbofan style aircraft engine to deliver suitable or desired performance, the clearance diameter containing the hybrid powerplant components and the airflow path configuration should be constructed so that the airflow path is efficient, free of obstructions, and carefully designed to manage airflow with minimal drag losses. The clearance diameter may also feature a housing having an outside skin that is in contact with the high-speed airflow which is smooth, which may be rigid, and which may be completely or generally continuous and / or sealed to minimize or control any air passing from outside the clearance diameter to inside.

[0047] Various elements of a hybrid powerplant system may be located inside the clearance diameter, such as motor / generator(s) or emachine(s). In various embodiments, the hybrid system may comprise a single motor / generator that is round or substantially round and may be substantially the same diameter as the inside of the clearance diameter. In other cases, to achieve the design requirements of power output while matching requirements for generator RPM, size, and power, embodiments may include multiple smaller motor / generators. These may be arranged with a geometry that enables multiple motor / generators to fit inside the clearance diameter. In one embodiment, there may be 2, 3, 4, 5, 6 or more generators arranged in a single plane similar to the revolver of a gun. There may even be more than one row of motor / generators such as shown in the example of Fig. 2. This may provide for, for example, generators that are each a smaller diameter enabling a higher operating RPM featuring higher efficiency and / or higher available power output for a given package size.-12- ACTIVE 712259322v2

[0048] Similar to the motor / generator or emachine, inverter(s) that convert AC to DC and may be used to control the motor / generators or emachines may also be advantageously placed inside the clearance diameter and out of the airflow bypass path. Such placement may result in reduced weight compared to other locations for the inverters such as outside of a nacelle or duct of a hybrid powerplant. Another advantage of locating the inverters inside the clearance diameter and proximal to the generators may be a substantial reduction of harmful EMI emissions related to the high-speed switching of high voltage associated with power generation.

[0049] Like the motor / generators and the inverters, there may be advantages in a hybrid-electric powerplant architecture from a careful application of gearing and gearbox principles and placement of that gearing within the clearance diameter and out of the bypass airflow path. Placing such gearing elements in line or generally in line with (e.g., within the clearance diameter, out of the bypass airflow path (even if not directly in line with other components)) the turbine engine, inside the nacelle / duct / air stream, and / or inside the clearance diameter may be useful in improving overall product effectiveness (weight, performance, efficiency, and reliability).

[0050] Finally, items such as high voltage connections including bus bars and HV wiring, low voltage wiring, cooling and lubrication fluids, and other system elements may be advantageously placed inside the clearance diameter near the hybrid architecture components and protected from the high velocity air stream of the bypass airflow. In addition, placing such components within the clearance diameter inside a nacelle or duct may also reduce the amount of bus bars, wiring, piping for cooling / lubrication fluids, cooling / lubrication fluids themselves, etc. used in a system This may reduce the overall weight of the system as well, as placing the hybrid powerplant components close together reduces the need for as much connective wiring, bus bars, piping and associated fluids, etc. between components.

[0051] Various embodiments for different architectures, power levels, and / or turbine engines may also include:( 1 ) The clearance diameter as defined herein may vary along the length of the hybrid architecture, it may not be a single diameter. The clearance diameter may grow and reduce across an axis of the turbine engine or nacelle as needed to effectively manage airflow and to clear the various hybrid components. See,-13- ACTIVE 712259322v2for example, Fig. 4 for an example of an airflow path that does not have a same diameter for the entire length of the airflow path.(2) The clearance diameter does not necessarily need to be round in cross section nor cylindrical all along its length. In various embodiments, it may be advantageous to stretch the clearance diameter into oblong or other cross sections along its length and / or to grow local blisters to clear a single component or element of a component. These changes to cross-section and addition of blisters does not detract from the core principle of using a continuous surface to wrap all hybrid components, providing an efficient path for high-velocity and thrust-producing bypass airflow.(3) The elements of a blended turbofan hybrid architecture may be packaged in various places, (e.g., they may be packaged downstream of the bypass fan or between the fan and the turbine engine in front of the fan, between fan and engine, aft or downstream of the engine, or any combination thereof). Such arrangement forward of the fan or aft of the engine may still feature a cylindrical package with minimized cross-sectional area which may advantageously interact with the high-speed airflow associated with forward flight and turbofan thrust.(4) Hybrid architectures using the benefits of the embodiments herein at high power levels may utilize packaging of some items outside the duct. An example includes placing the inverters outside and motors inside with high voltage phase wires passing through streamlined struts or other low-drag connections.Another example may include passing cooling fluids from the pumps and devices inside the clearance diameter to the outside of the bypass air duct to interact with heat exchangers.(5 ) Example of diameters for outside diameters (OD) of a fan or bypass fan that may be used in various embodiments may include ODs of anywhere from 24” to 72”, such as any of 24”, 36”, 40”, 44”, 48”, 52”, 56”, 60”, 66”, and / or 72”.(6) Example of diameters for inside diameters (ID) of fans that may form an outer edge or boundary' of a clearance diameter may include IDs of anywhere from 12” to 30”, such as any of 12”, 15”, 18”, 21”, 24”, 27”, and / or 30”.-14- ACTIVE 712259322v2

[0052] The image below shows an example embodiment of how the elements of a hybrid powerplant may be packaged to include many elements in the package but still provide bypass fan airflow.

[0053] Fig. 1 illustrates an example aerospace hybrid powerplant 100 with a majority of the aerospace hybrid powerplant 100 within a nacelle 105. As such, Fig. 1 shows an example embodiment of how the elements of the hybrid powerplant 100 may be packaged to include many elements in the package but still provide bypass fan 115 airflow through the nacelle. The bypass fan 115 may draw' air through an inlet 145 and through a bypass airflow path 150. The air then eventually passes through an outlet 155. Various elements may be placed within a clearance diameter and generally out of the bypass airflow' path 150. Such elements may include a turbine engine 110 and housing 135 that contains gearing or a gearset that connects an output of the turbine engine 110 to emachines such as emachines 120 and 125. Other elements inside of the clearance diameter may include an emachine 130 that is connected to a gear of a power blending gearset inside housing 140. In this way, various components may be within or surrounded by the nacelle 105 but out of or not wdthin a bypass airflow' path 150.

[0054] In the example of Fig. 1, a portion of the turbine engine 110 is outside of the nacelle 105. However, in various embodiments, the turbine engine 110 may be fully inside of the nacelle 105, fully outside of the nacelle 105, or partially outside as shown in Fig. 1. In various embodiments, other aspects of the hybrid pow'erplant may be fully, partially, or not all inside the nacelle and / or turbofan duct. However, as shown with respect to the turbine engine 110 in Fig. 1, even if a component of the hybrid pow erplant comes out the back of the nacelle 105 or duct, the component may still be w’ithin a clearance diameter (e.g., out of the bypass airflow' path).

[0055] Fig. 2 illustrates an example aerospace hybrid powerplant 200 w'here less than a majority of the aerospace hybrid pow'erplant 200 is wdthin a nacelle 205. The bypass fan 210 may push air into an inlet 215 and out an outlet 220 of the nacelle 205. The hybrid powerplant 200 may also have structural supports 225 connecting components of the hybrid pow’erplant 200 such as a turbine engine 202 to the nacelle 205. The structural components may be designed to permit air to flow' through so as to minimally cause drag to and impede flow’ of air through the bypass airflow’ path.-15- ACTIVE 712259322v2

[0056] The embodiment of Fig. 2 further includes numerous motor / generators or emachines 205 and 207. The emachines 205 are located outside of the nacelle 205 but still within a clearance diameter and out of the bypass airflow path. The emachines 207 are located within or inside the nacelle 205 and still within a clearance diameter and out of the bypass airflow path. More than half of the turbine engine 202 is outside of the nacelle 205.

[0057] In various embodiments, the nacelle 205 may be a turbofan duct that is inside a larger nacelle or housing (not pictured). In other words, multiple housings may be present. However, in various embodiments that have multiple housings, the bypass airflow path may be configured to only be a single path between two housings.

[0058] In various embodiments, structural supports such as the supports 225 may also have embedded within them other useful elements or components, such as piping for coolant, fuel, or other fluids; wires, conductors, or bus bars; and / or any other connective component for connecting components of the hybrid powerplant 200 to other components on an aircraft or otherwise outside of the hybrid powerplant 200.

[0059] Fig. 3 illustrates an example aerospace hybrid powerplant 300 with an entirety of the aerospace hybrid powerplant 300 within a nacelle 325. The aerospace hybrid powerplant 300 also includes a bypass fan 320 configured to generate thrust by directing inlet airflow 305 along a bypass air path within the nacelle 325. Components of the hybrid powerplant such as power blend gearing 355, a shaft 340, inverters 370, inverter 375, motor / generators 380, motor / generator 385, and power take off gearing 365 may be within a housing 345. The outside of the housing 345 may form an inner boundary of the bypass airflow path. An inside surface of the nacelle 325 may form an outer boundary of the bypass airflow path. The outer edge of the housing 345 may correspond to a clearance diameter within with the hybrid powerplant components are placed.

[0060] An engine 360 may be configured to output mechanical power to the bypass fan 320. The motor / generators 380 or emachines may be configured to receive mechanical power from the engine and output electrical power to a respective one of the inverters 370. The inverters 370 may output that electrical power through wiring, bus bars, etc. to another device of an aircraft (e.g., electric motors, batteries, etc.). The motor / generators 380 or emachines may be further configured to receive electrical power through their respective inverters 370 (e.g., from batteries on the aircraft) and-16- ACTIVE 712259322v2output mechanical power to the bypass fan 320 via the power blend gearing 355 and the shaft 340. The power blend gearing 355 is configured to output a blend of mechanical power to the bypass fan from the engine 360 and the motor / generators 380 or emachines. In Fig. 3, each of the inverters 370 and 375, the plurality of motor / generators 380 / 385 or emachines, and the power blend gearing 355 is positioned within the nacelle 325 and out of the bypass air path.

[0061] The engine 360 is also in its own housing 350 in the example of Fig. 3. The housing 350 and the housing 345 may form an opening 390 to allow a percentage of airflow 310 to pass into the engine 360, as the engine may be an air breathing engine that needs an intake of air to function properly, ''efficiently. In various embodiments, the opening 390 may be formed by a static or unmoving portions of the housings 345 and 350. However, in other embodiments, an opening into an airbreathing engine may be variable (e.g., using motors controllable by a controller, based on movable parts configured to open or close more based on airspeed or other environmental factors present within the bypass airflow path). As such, if a percentage of airflow 310 passes into the engine, a resulting percentage of airflow 315 may then be output at the back of the nacelle 325.

[0062] The shaft 340 may also be, in various embodiments including that of Fig. 3, generally coaxial with the nacelle 325. In this way, since the shaft 340 (or component parts of the shaft 340) run from the engine 360 to the fan 320, the shaft 340 itself is within the housing 345 and the clearance diameter of the system. In addition, other components like the inverters 370 / 375, the motor / generators 380 / 385, etc. may be placed around the shaft 340 so that all the components of the system as desired can fit within a clearance diameter and the housing 345. In the embodiment of Fig. 4, the clearance diameter may include the housing 345 and everything within the housing 345. An axis of the nacelle 325 may therefore also be at the center of the clearance diameter (as well as the shaft 340).

[0063] Fig. 4 illustrates an example of an irregular bypass air path 415. Although Fig.4 does not show hybrid powerplant components, Fig. 4 demonstrates how a turbofan duct or nacelle may have an irregular bypass airflow path 415 that is not cylindrical. Though the airflow path 415 is only shown with respect to a turbine engine, an airflow path of the various embodiments described and shown herein may also be irregular adjacent to-17- ACTIVE 712259322v2where other components of a hybrid powerplant are placed (e.g., adjacent to emachines, gearing or gearsets, inverters, etc.). The bypass airflow path 415 may be formed by an outside edge or side of an inner housing 410 and an inside edge or side of an outer housing 405. The outer housing 405 may be a turbofan duct or nacelle. In various embodiments, there may be another nacelle outside of the outer housing 405. That other nacelle may be more cylindrical and less irregular in shape to reduce drag of the overall hybrid powerplant with respect to environmental air while an aircraft is in flight.

[0064] At least some aspects of the present disclosure will now be described with reference to the following numbered clauses.1. An aerospace hybrid powerplant comprising:a nacelle;a bypass fan configured to generate thrust by directing airflow along a bypass air path within the nacelle;an engine configured to output mechanical power to the bypass fan; and at least one electric machine configured to:output electrical power, oroutput mechanical power to the bypass fan;wherein:the engine is positioned within the nacelle and out of the bypass air path, andthe at least one electric machine is positioned within the nacelle and out of the bypass air path.2. The aerospace hybrid powerplant of clause 1, further comprising a power transmission system operatively coupled to the engine, the bypass fan, and the at least one electric machine, wherein the power transmission system is configured to selectively distribute mechanical power output by the engine between the bypass fan and the at least one electric machine, and wherein the power transmission system is positioned within the nacelle and out of the bypass air path.3. The aerospace hybrid powerplant of clauses 1 or 2, further comprising at least one inverter electrically coupled to the at least one electric machine, wherein the at least one inverter is positioned within the nacelle and out of the bypass air path.-18- ACTIVE 712259322v24. The aerospace hybrid powerplant of clause 3. wherein:the at least one electric machine comprises a first electric machine and a second electric machine,the at least one inverter comprises a first inverter and a second inverter, the first inverter is electrically coupled to the first electric machine,the second inverter is electrically coupled to the second electric machine, and each of the first electric machine, the second electric machine, the first inverter, and the second inverter are within the nacelle and out of the bypass air path.5. The aerospace hybrid powerplant of clauses 1 to 4, wherein each of the engine and the at least one electric machine are positioned within a threshold radial distance of an axis of the nacelle.6. The aerospace hybrid powerplant of clauses 1 to 5, further comprising a power blend gearset configured to blend mechanical output power to the bypass fan from the engine and the at least one electric machine, wherein the gearing is positioned within the nacelle and out of the bypass air path.7. The aerospace hybrid powerplant of clause 6, further comprising a power take off gearset configured to connect an output shaft of the engine to an input shaft of the at least one electric machine.8. The aerospace hybrid powerplant of clauses 1 to 7, wherein the bypass air path comprises a generally cylindrical air path through the nacelle.9. The aerospace hybrid powerplant of clauses 1 to 8, further comprising an inner housing surrounding the engine and the at least one electric machine, wherein the nacelle comprises an outer housing of the aerospace hybrid powerplant, and wherein the bypass air path is defined between the inner housing and the outer housing.10. The aerospace hybrid powerplant of clause 9, further comprising at least one inverter, a power blend gearset, and a power blend motor / generator configured to control the power blend gearset, wherein each of the at least one inverter, the power blend gearset, and the power blend motor / generator are each surrounded by the inner housing.-19- ACTIVE 712259322v211. The aerospace hybrid powerplant of clauses 1 to 10, wherein the bypass air path is outside of a clearance diameter positioned inside of the nacelle12. The aerospace hybrid powerplant of clauses 1-11, further comprising a cooling system configured to direct airflow from the bypass air path toward at least one of: the at least one electric machine;the engine; ora heat exchanger associated with the at least one electric machine, the engine, or an inverter electrically coupled to the at least one electric machine.13. The aerospace hybrid powerplant of clauses 11 or 12, wherein the heat exchanger is positioned within the nacelle and out of the bypass air path.14. The aerospace hybrid powerplant of clauses 1 to 13, wherein the nacelle is configured to mount under a wing of an aircraft, on top of the wing of the aircraft, or on a fuselage of the aircraft.15. The aerospace hybrid powerplant of clauses 1 to 14, wherein the at least one electric machine is configured to operate as both a motor and a generator.16. An aerospace hybrid powerplant comprising:a nacelle;a bypass fan configured to generate thrust by directing airflow along a bypass air path within the nacelle;an engine configured to output mechanical power to the bypass fan; and at least one electric machine configured to:output electrical power, oroutput mechanical power to the bypass fan; andat least one inverter electrically coupled to the at least one electric machine; wherein:the engine is positioned within the nacelle and out of the bypass air path, andthe at least one electric machine is positioned within the nacelle and out of the bypass air path.-20- ACTIVE 712259322v217. The aerospace hybrid powerplant of clause 16, further comprising an engine configured to output mechanical power to the bypass fan, wherein the engine is positioned at least in part within the nacelle and out of the bypass air path.18. The aerospace hybrid powerplant of clause 17, wherein a portion of the engine is positioned outside of the nacelle.19. The aerospace hybrid powerplant of clauses 16 to 18, further comprising a power blend gearset configured to blend mechanical output power to the bypass fan from the engine and the at least one electric machine, wherein the gearing is positioned within the nacelle and out of the bypass air path.20. An aerospace hybrid powerplant comprising:a nacelle;a bypass fan configured to generate thrust by directing airflow along a bypass air path within the nacelle;an engine configured to output mechanical power to the bypass fan; and a plurality of inverters;a plurality of electric machines each configured to:receive mechanical power from the engine and output electrical power to an inverter of the plurality of inverters, andreceive electrical power through the inverter and output mechanical power to the bypass fan; anda power blend gearset configured to output a blend of mechanical power to the bypass fan from the engine and the plurality of electric machines, wherein each of the plurality of inverters, the plurality of electric machines, and the power blend gearset is positioned within the nacelle and out of the bypass air path.

[0065] As such, although certain example methods and apparatus have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus, and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.-21- ACTIVE 712259322v2

[0066] Many illustrative embodiments are further listed below as the claim set in accordance with one or more aspects disclosed herein. Many of the embodiments listed below are described as depending from various embodiments and the dependencies are not limited and may be depending from any of the embodiments as is described and contemplated by this disclosure. Moreover, that any one or more of the listed embodiments may be incorporated into one or more of the other embodiments is contemplated by this disclosure.

[0067] The present technology is disclosed above and in the accompanying drawings with reference to a variety of embodiments. The purpose served by the disclosure, however, is to provide an example of the various features and concepts related to the technology, not to limit its scope. One skilled in the relevant art will recognize that numerous variations and modifications may be made to the embodiments described above without departing from the scope of the present invention, as defined by the appended claims.ACTIVE 712259322v2

Claims

CLAIMSWhat is claimed is:

1. An aerospace hybrid powerplant comprising:a nacelle;a bypass fan configured to generate thrust by directing airflow along a bypass air path within the nacelle;an engine configured to output mechanical power to the bypass fan; and at least one electric machine configured to:output electrical power, oroutput mechanical power to the bypass fan;wherein:the engine is positioned within the nacelle and out of the bypass air path, andthe at least one electric machine is positioned within the nacelle and out of the bypass air path.

2. The aerospace hybrid powerplant of claim 1, further comprising a power transmission system operatively coupled to the engine, the bypass fan, and the at least one electric machine, wherein the power transmission system is configured to selectively distribute mechanical power output by the engine between the bypass fan and the at least one electric machine, and wherein the power transmission system is positioned within the nacelle and out of the bypass air path.

3. The aerospace hybrid powerplant of claim 1, further comprising at least one inverter electrically coupled to the at least one electric machine, wherein the at least one inverter is positioned within the nacelle and out of the bypass air path.

4. The aerospace hybrid powerplant of claim 3, wherein:the at least one electric machine comprises a first electric machine and a second electric machine,the at least one inverter comprises a first inverter and a second inverter,-23- ACTIVE 712259322v2the first inverter is electrically coupled to the first electric machine,the second inverter is electrically coupled to the second electric machine, and each of the first electric machine, the second electric machine, the first inverter, and the second inverter are within the nacelle and out of the bypass air path.

5. The aerospace hybrid powerplant of claim 1, wherein each of the engine and the at least one electric machine are positioned within a threshold radial distance of an axis of the nacelle.

6. The aerospace hybrid powerplant of claim 1, further comprising a power blend gearset configured to blend mechanical output power to the bypass fan from the engine and the at least one electric machine, wherein the gearing is positioned within the nacelle and out of the bypass air path.

7. The aerospace hybrid powerplant of claim 6, further comprising a power take off gearset configured to connect an output shaft of the engine to an input shaft of the at least one electric machine.

8. The aerospace hybrid powerplant of claim 1, wherein the bypass air path comprises a generally cylindrical air path through the nacelle.

9. The aerospace hybrid powerplant of claim 1, further comprising an inner housing surrounding the engine and the at least one electric machine, wherein the nacelle comprises an outer housing of the aerospace hybrid powerplant, and wherein the bypass air path is defined between the inner housing and the outer housing.

10. The aerospace hybrid powerplant of claim 9, further comprising at least one inverter, a power blend gearset, and a power blend motor / generator configured to control the power blend gearset, wherein each of the at least one inverter, the power blend gearset, and the power blend motor / generator are each surrounded by the inner housing.

11. The aerospace hybrid powerplant of claim 1, wherein the bypass air path is outside of a clearance diameter positioned inside of the nacelle12. The aerospace hybrid powerplant of claim 1, further comprising a cooling system configured to direct airflow from the bypass air path toward at least one of:-24- ACTIVE 712259322v2the at least one electric machine;the engine; ora heat exchanger associated with the at least one electric machine, the engine, or an inverter electrically coupled to the at least one electric machine.

13. The aerospace hybrid powerplant of claim 11, wherein the heat exchanger is positioned within the nacelle and out of the bypass air path.

14. The aerospace hybrid powerplant of claim 1, wherein the nacelle is configured to mount under a wing of an aircraft, on top of the wing of the aircraft, or on a fuselage of the aircraft.

15. The aerospace hybrid powerplant of claim 1, wherein the at least one electric machine is configured to operate as both a motor and a generator.

16. An aerospace hybrid powerplant comprising:a nacelle;a bypass fan configured to generate thrust by directing airflow along a bypass air path within the nacelle;an engine configured to output mechanical power to the bypass fan; and at least one electric machine configured to:output electrical power, oroutput mechanical power to the bypass fan; andat least one inverter electrically coupled to the at least one electric machine; wherein:the engine is positioned within the nacelle and out of the bypass air path, andthe at least one electric machine is positioned within the nacelle and out of the bypass air path.

17. The aerospace hybrid powerplant of claim 16, further comprising an engine configured to output mechanical power to the bypass fan, wherein the engine is positioned at least in part within the nacelle and out of the bypass air path.-25- ACTIVE 712259322v218. The aerospace hybrid powerplant of claim 17, wherein a portion of the engine is positioned outside of the nacelle.

19. The aerospace hybrid powerplant of claim 16, further comprising a power blend gearset configured to blend mechanical output power to the bypass fan from the engine and the at least one electric machine, wherein the gearing is positioned within the nacelle and out of the bypass air path.

20. An aerospace hybrid powerplant comprising:a nacelle;a bypass fan configured to generate thrust by directing airflow along a bypass air path within the nacelle;an engine configured to output mechanical power to the bypass fan; and a plurality of inverters;a plurality of electric machines each configured to:receive mechanical power from the engine and output electrical power to an inverter of the plurality of inverters, andreceive electrical power through the inverter and output mechanical power to the bypass fan; anda power blend gearset configured to output a blend of mechanical power to the bypass fan from the engine and the plurality of electric machines, wherein each of the plurality of inverters, the plurality of electric machines, and the power blend gearset is positioned within the nacelle and out of the bypass air path.-26- ACTIVE 712259322v2

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