Motor assistance for multi-shaft turbine operation and control

Abstract

A multi-spool turbine is provided having an electric motor that can be controlled to input power to one of the turbine's shafts. In one aspect, the multi-spool turbine can be a hybrid electric gas turbine engine for an aircraft. The hybrid electric gas turbine engine can include a first shaft, a second shaft, and an electric motor operably coupled to the first shaft. In response to an increase in thrust demand, the electric motor receives power from a power source. In turn, the electric motor applies torque to the first shaft, thereby increasing the rotational speed of the first shaft. In this way, the electric motor can electrically assist the turbine to meet the increase in thrust demand.

Description

Technical Field

[0001] The present disclosure generally relates to a multi-shaft turbine having at least one electric machine operable to facilitate operation and control thereof. Background Art

[0002] For multi-spool gas turbine engines used in aircraft, engine efficiency depends at least in part on the clearances between rotating and stationary components, such as rotating turbine blades and stationary shrouds. Generally, the tighter the clearance between the tips of the blades and the shroud (i.e., the more closed the clearance), the more efficiently the gas turbine engine operates. Therefore, minimizing blade tip clearance contributes to optimal engine performance and efficiency.

[0003] One challenge in minimizing blade tip clearance is that when thrust demand increases or decreases, turbine blades expand and contract at different rates than the shrouds and casings that circumferentially surround them. Therefore, conventionally, blade tip clearances are left more open to account for bursts and accelerations of the engine, particularly during the cruise phase of flight. Indeed, the size of the cruise clearance is typically determined so that the engine can perform a phase climb without suffering from turbine blade rubbing. Friction events may result in reduced engine performance and efficiency, may reduce the effective service life of the turbine blades and / or shrouds, and may deteriorate the exhaust temperature margin of the engine. Therefore, ideally, the blade tip clearance is set to minimize the gap between the blade tip and the shroud without the turbomachinery components suffering from friction events.

[0004] In some cases, the engine is controlled so that the engine's thrust increase rate is limited, particularly during cruise operation. This allows the clearances to be set tighter than would otherwise be the case, and therefore, better engine efficiency can be achieved during cruise operation. However, limiting the engine's thrust increase rate reduces the engine's responsiveness, which may be undesirable to the pilot and crew.

[0005] Therefore, a multi-spool turbine that addresses one or more of the challenges described above would be useful. Furthermore, an aircraft having at least one multi-spool gas turbine engine that addresses one or more of the challenges described above would be advantageous. Furthermore, a method of operating a multi-spool turbine that addresses one or more of the challenges described above would be beneficial. Summary of the invention

[0006] Aspects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.

[0007] In one aspect, a vehicle is provided. The vehicle includes a gas turbine engine. The gas turbine engine includes a first rotatable component and a second rotatable component. The gas turbine engine also includes a motor operably coupled to the first rotatable component and in communication with a power source. The motor is operable to receive power from the power source. In addition, the vehicle includes a computing system having one or more processors and one or more storage devices, the one or more storage devices storing instructions that, when executed by the one or more processors, cause the one or more processors to perform operations, and when performing the operations, the one or more processors are configured to: receive an input indicating a change in thrust demand for the gas turbine engine; and in response to the received input indicating a change in thrust demand for the gas turbine engine, cause the motor to change the applied torque on the first rotatable component, thereby changing the rotational speed of the first rotatable component.

[0008] In another aspect, a turbomachine for a vehicle is provided. The turbomachine includes a first rotatable component, a second rotatable component, and an electric machine operably coupled to the first rotatable component. The turbomachine also includes a controller having one or more processors and one or more storage devices, the one or more storage devices storing instructions that, when executed by the one or more processors, cause the one or more processors to perform operations, wherein when performing the operations, the one or more processors are configured to: receive an input indicating an increase in thrust demand for the turbomachine; and in response to the increase in thrust demand for the turbomachine, cause the electric machine to apply torque to the first rotatable component.

[0009] In another aspect, a method is provided. The method includes receiving, by one or more computing devices, input indicating an increase in thrust demand for a multi-spool turbine having a first spool and a second spool. In response to the received input indicating an increase in thrust demand for the multi-spool turbine, the method also includes causing, by the one or more computing devices, a motor operably coupled to the first spool to increase a rotational speed of the first spool.

[0010] In another aspect, a non-transitory computer-readable medium is provided. The non-transitory computer-readable medium includes computer-executable instructions that, when executed by one or more processors of a computing system, cause the one or more processors to: receive input indicating an increase in thrust demand for a multi-spool turbine having a first rotatable component and a second rotatable component, such as a first spool and a second spool, respectively; and in response to receiving the input indicating an increase in thrust demand for the multi-spool turbine, cause a motor operably coupled to the first spool to increase a rotational speed of the first spool.

[0011] In some embodiments, when the computer executable instructions are executed by one or more processors of a computing system, the one or more processors cause a motor to increase the rotational speed of a first spool independently of a second spool.

[0012] In some embodiments, when the computer executable instructions are executed by one or more processors of a computing system, the one or more processors cause the motor to increase the rotational speed of the first spool to substantially meet the thrust demand, and wherein as the current flowing to the motor decreases during the first time period, the one or more processors cause the fuel flow to the multi-spool turbine to increase during the first time period.

[0013] These and other features, aspects and advantages of the subject matter will be better understood with reference to the following description and appended claims.The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the subject matter and, together with the description, explain the principles of the subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] A full and enabling disclosure of the subject matter, including the best mode of the invention, is set forth in the specification, which refers to the accompanying drawings, wherein:

[0015] Figure 1 A schematic cross-sectional view of an exemplary gas turbine engine according to an exemplary aspect of the present disclosure is provided;

[0016] Figure 2 Provided Figure 1 A schematic diagram of a gas turbine engine and depicting an electrical system in communication with the gas turbine engine;

[0017] Figure 3 Provides control Figure 1 and Figure 2 A block diagram of a control system of a gas turbine engine;

[0018] Figure 4 A block diagram of an example thrust requirement plan according to an exemplary aspect of the present disclosure is provided;

[0019] Figure 5 A graph depicting thrust demand during a first time period is provided according to an exemplary aspect of the present disclosure;

[0020] Figure 6 providing a graph depicting torque applied by the motor during a first time period;

[0021] Figure 7 providing a graph depicting fuel flow to a gas turbine engine during a first time period;

[0022] Figure 8 A graph depicting thrust demand during a first time period is provided according to an exemplary aspect of the present disclosure;

[0023] Fig. 9providing a graph depicting torque applied by the motor during a first time period;

[0024] Fig.10 providing a graph depicting fuel flow to a gas turbine engine during a first time period;

[0025] Fig.11 A schematic diagram of a core turbine engine of another gas turbine engine according to an example embodiment of the present disclosure is provided;

[0026] Fig.12 A schematic diagram of a core turbine engine of another gas turbine engine having a control system according to an exemplary embodiment of the present disclosure is provided;

[0027] Fig.13 A flow chart of an exemplary method (400) of operating a hybrid-electric multi-shaft turbine according to an exemplary embodiment of the present disclosure is provided;

[0028] Fig.14 An example computing system according to an example embodiment of the present disclosure is provided; and

[0029] FIG. 15 provides an example vehicle according to an example embodiment of the present disclosure. DETAILED DESCRIPTION

[0030] Reference will now be made in detail to the current embodiments of the invention, one or more examples of which are shown in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. The same or similar designations have been used to refer to the same or similar parts of the invention in the drawings and description. As used herein, the terms "first", "second" and "third" may be used interchangeably to distinguish one component from another, and are not intended to indicate the location or importance of the respective components. The terms "upstream" and "downstream" refer to the relative flow direction relative to the flow of a fluid in a fluid path. For example, "upstream" refers to the flow direction from which the fluid flows, while "downstream" refers to the flow direction to which the fluid flows. In addition, as used herein, the terms "axial" or "axially" refer to a dimension along the longitudinal axis of the engine. The term "front" used in conjunction with "axial" or "axially" refers to a direction toward the engine inlet, or a component is relatively closer to the engine intake than another component. The term "rear" used in conjunction with "axial" or "axially" refers to a direction toward the engine nozzle, or a component is relatively closer to the engine nozzle than another component. The term "radial" or "radially" refers to a dimension extending between the central longitudinal axis of the engine and the outer circumference of the engine. In addition, as used herein, unless otherwise specified, approximate terms such as "approximately", "substantially" or "approximately" refer to within a fifteen percent (15%) error range.

[0031] In general, the present disclosure relates to a multi-spool turbine having an electric motor that can be controlled to input power to one of the turbine's spools. In one aspect, the multi-spool turbine can be a hybrid electric gas turbine engine for an aircraft. The hybrid electric gas turbine engine may include a first spool that can rotate about a first axis of rotation and a second spool that can rotate about a second axis of rotation, and the second axis of rotation may be the same as or different from the first axis of rotation. In some embodiments, the first spool may be a low-pressure spool and the second spool may be a high-pressure spool. In other embodiments, the first spool may be a high-pressure spool and the second spool may be a low-pressure spool. The motor is or may be operable as an electric motor. The motor may receive power from a power source such as one or more batteries and / or an auxiliary power unit. The motor is operably coupled to the first spool. When the motor receives power from the power source, the motor applies torque to the first spool, which causes the rotational speed of the first spool to change.

[0032] In response to an increase in thrust demand (e.g., an engine burst), one or more processors of the computing system may cause the motor to apply torque to the first spool. In some embodiments, the motor may initially meet all or a percentage of the thrust demand increase. In response to the increase in thrust demand, current may be provided to the motor almost instantaneously or at a predefined rate. The torque applied by the motor on the first spool "accelerates" or increases the speed of the first spool. The fuel input to the combustor of the multi-spool turbine may be gradually increased or increased, while the torque applied by the motor to the first spool may be reduced or decreased over a period of time. Thus, the use of the motor may be reduced so that the fuel input may eventually meet the required thrust increase without the use of the motor. In this way, the motor may electrically assist the engine in meeting the thrust demand while reducing the rotor expansion of the second spool and limiting the rate at which the speed of the second spool increases. Thus, the engine may respond to an increase in thrust demand without causing a turbomachinery friction event.

[0033] Furthermore, advantageously, by utilizing an electric motor to assist in meeting the thrust required during engine acceleration or burst, the engine can be operated in cruise operation such that the compressor (e.g., a high pressure compressor) of the gas turbine engine is operated closer to the stall line due to the need for less headroom or stall margin to account for the acceleration of the second or high pressure spool. Operating the compressor closer to the stall line provides an increased pressure ratio, which equates to reduced fuel burn. Thus, using an electric motor for electrical assistance during cruise operation can provide increased thermal efficiency during cruise operation while protecting the engine from stalling under all conditions.

[0034] In other embodiments, in response to the thrust demand increase, the computing system may cause the motor to apply torque to the first spool. In particular, the computing system may cause the motor to meet all increases in thrust demand, and in such embodiments, the motor may continue to meet the increase in thrust demand without any additional fuel input. For example, in some embodiments, particularly during cruise operation, the fuel input may be limited to a predefined fuel input threshold. In such embodiments, if the fuel input reaches or is at a predefined fuel input threshold and an increase in thrust demand is required, the increased thrust demand may be fully met by the motor. When the fuel input drops below the predefined fuel input threshold, fuel may be input into the gas turbine engine (e.g., its combustor), and the motor may be used for electrical assistance to meet the increase in thrust demand. In some embodiments, the predefined fuel input threshold is set based on one or more operating conditions associated with the engine and / or the aircraft. For example, the predefined fuel input threshold may vary based on, but not limited to, the altitude of the aircraft, the airspeed or Mach number of the aircraft, the ambient temperature, the electrical energy stored in the power source, the amount of remaining fuel, the weight of the aircraft, a combination thereof, and / or other flight / engine conditions.

[0035] In other embodiments, in response to a reduction in thrust demand (e.g., engine deceleration), one or more processors of the computing system may cause the motor to change the applied torque on the first spool. In such an embodiment, the one or more processors may cause the motor to change the applied torque on the first rotatable component. When the one or more processors cause the motor to reduce the torque on the first rotatable component, or cause the motor to act as a generator to apply a drag torque on the first rotatable component, the rotational speed of the first rotatable component is reduced. In this way, the turbine can decelerate faster. As described above, the one or more processors may: 1) cause the motor to apply a smaller torque on the first rotatable component when the motor is used as a motor, for example, to reduce the rotational speed of the first rotatable component; and / or 2) cause the motor to act as a generator to apply a drag or counter torque on the first rotatable component to reduce the rotational speed of the first rotatable component. Using at least one method, the rotational speed of the first rotatable component can be reduced instantaneously or almost instantaneously.

[0036] Figure 1 A schematic cross-sectional view of an exemplary turbine is provided that may incorporate various embodiments of the present disclosure. In particular, Figure 1 An aviation high bypass turbofan engine, referred to herein as “turbofan 10 ”, is provided. Figure 1The turbofan 10 can be mounted to an aircraft, such as a fixed-wing aircraft, and can generate thrust for propelling the aircraft. For reference, the turbofan 10 defines an axial direction A, a radial direction R, and a circumferential direction. In addition, the turbofan 10 defines an axial centerline or longitudinal axis 12, which extends through it for reference purposes. Typically, the axial direction A extends parallel to the longitudinal axis 12, the radial direction R extends outwardly and inwardly from the longitudinal axis 12 in a direction perpendicular to the axial direction A, and the circumferential direction extends three hundred and sixty degrees (360°) around the longitudinal axis 12.

[0037] The turbofan 10 includes a core gas turbine engine 14 and a fan section 16 located upstream thereof. The core engine 14 includes a tubular casing 18 that defines an annular core inlet 20. The casing 18 further surrounds and supports a boost or low-pressure compressor 22 that pressurizes the air entering the core engine 14 through the core inlet 20. A high-pressure multi-stage axial compressor 24 receives pressurized air from the LP compressor 22 and further increases the air pressure. The pressurized air flows downstream to a combustor 26, where fuel is injected into the pressurized air flow and ignited to increase the temperature and energy level of the pressurized air. High-energy combustion products flow downstream from the combustor 26 to a high-pressure turbine 28 for driving the high-pressure compressor 24 through a high-pressure spool 30 or a second rotatable component. The high-energy combustion products then flow to a low-pressure turbine 32 for driving the LP compressor 22 and the fan section 16 through a low-pressure spool 34 or a first rotatable component. In the exemplary embodiment, LP spool 34 is coaxial with HP spool 30. After driving each turbine 28 and 32, the products of combustion exit core engine 14 through exhaust nozzle 36 to produce propulsive thrust.

[0038] The fan section 16 includes a rotatable axial flow fan rotor 38, which is surrounded by an annular fan case 40. The fan case 40 is supported by a plurality of substantially radially extending, circumferentially spaced outlet guide vanes 42 by the core engine 14. In this way, the fan case 40 surrounds the fan rotor 38 and a plurality of fan blades 44. The downstream section 46 of the fan case 40 extends above the outside of the core engine 14 to define a bypass passage 48. The air passing through the bypass passage 48 provides propulsion thrust, as will be further explained below. In some alternative embodiments, the LP spool 34 may be connected to the fan rotor 38 via a reduction gearbox such as an indirect drive or gear drive configuration. As needed or required, such a reduction gear may be included between any suitable shafts / spools within the turbofan 10.

[0039] During operation of turbofan 10, an initial or incoming airflow, represented by arrows 50, enters turbofan 10 through an inlet 52 defined by fan case 40. Airflow 50 passes through fan blades 44 and is split into a first airflow (represented by arrows 54) that moves through bypass passage 48 and a second airflow (represented by arrows 56) that enters LP compressor 22 through core inlet 20.

[0040] The pressure of the second airflow 56 is gradually increased by the LP compressor 22 and then enters the HP compressor 24, as shown by arrow 58. The discharged pressurized air flows downstream to the combustor 26, where fuel is introduced to produce combustion gases or products. The combustion products 60 leave the combustor 26 and flow through the HP turbine 28. The combustion products 60 then flow through the LP turbine 32 and exit the exhaust nozzle 36 to generate thrust. Moreover, as described above, a portion of the incoming airflow 50 flows through the bypass passage 48 and flows through the outlet nozzle defined between the fan case 40 and the outer casing 18 at the downstream section 46 of the fan case 40. In this way, a large propulsive force is generated.

[0041] like Figure 1 As further shown, the combustor 26 defines an annular combustion chamber 62, which is generally coaxial with the longitudinal centerline axis 12, and an inlet 64 and an outlet 66. The combustor 26 receives an annular flow of pressurized air from a high pressure compressor discharge outlet 69. A portion of the compressor discharge air ("CDP" air) flows into a mixer (not shown). Fuel is injected from a fuel nozzle 68 to mix with the air and form a fuel-air mixture, which is provided to the combustion chamber 62 for combustion. Ignition of the fuel-air mixture is accomplished by a suitable igniter, and the resulting combustion gases 60 flow in an axial direction A toward and into an annular first stage turbine nozzle 72. The nozzle 72 is defined by an annular flow passage that includes a plurality of radially extending, circumferentially spaced nozzle vanes 74 that turn the gases so that they flow at an angle and impinge on the first stage turbine blades of the HP turbine 28. For this embodiment, the HP turbine 28 rotates the HP compressor 24 via an HP spool 30 , and the LP turbine 32 drives the LP compressor 22 and the fan rotor 38 via an LP spool 34 .

[0042] It is worth noting that for this embodiment, the turbofan 10 is an aero-electric hybrid propulsion machine. In particular, the turbofan 10 includes one or more electric motors that are operable to provide operation and control assistance to the multi-axis turbofan 10. Figure 1In the illustrated embodiment, the turbofan 10 includes an electric motor 110 operably coupled to the LP spool 34. Although the electric motor 110 is operably coupled to the LP spool 34 at the rear end of the LP spool 34, the electric motor 110 may be mounted to the LP spool 34 at any suitable location. As will be explained herein, during an engine burst, for example, the electric motor 110 may be controlled to apply torque to the LP spool 34, thereby increasing the rotational speed of the LP spool 34, independent of the HP spool 30. In other words, the electric motor 110 may be controlled to electrically assist the LP spool 34 in increasing its rotational speed to ultimately change the thrust output of the turbofan 10. The electric motor 110 may be controlled to electrically assist the LP spool 34 during transient operations, such as during a burst or acceleration in the cruise phase of flight. The manner in which the electric motor 110 may be used to electrically assist the LP spool 34 will be described in greater detail herein.

[0043] Despite Figure 1 The turbofan 10 has been described and shown as representing an example hybrid turbine, but the subject matter of the present disclosure may be applied to or combined with other suitable types of multi-spool turbines. For example, the subject matter of the present disclosure may be applied to or combined with other suitable turbine engines, such as steam and other gas turbine engines. Exemplary gas turbine engines may include turbojets, turboprops, turboshafts, aeroderivatives, auxiliary power units, etc. In addition, the subject matter of the present disclosure may be applied to turbines having more than two spools. For example, the inventive aspects of the present disclosure may be applied to a gas turbine engine for an aircraft having a high-pressure spool, a medium-pressure spool, and a low-pressure spool. As will be explained herein, the motor may be operably coupled to the low-pressure spool and may be controlled to apply torque thereto, for example, to increase the rotational speed of the low-pressure spool independently of the other spools. As described herein, the rotational speed of the medium-pressure spool and the high-pressure spool may be controlled or adjusted, for example, via increasing fuel input when increased thrust is required.

[0044] Figure 2 Provided Figure 1 1 and a control system 100 operable to control the turbofan 10 and its motor 110. The motor 110 is a component of the control system 100. In some embodiments, all components of the control system 100 are on the turbofan 10. In other embodiments, some components of the control system 100 are on the turbofan 10 and some are external to the turbofan 10. For example, some external components may be mounted to the wing, fuselage, or other suitable structure of the aircraft on which the turbofan 10 is mounted.

[0045] As shown, the motor 110 is operably coupled to the first or LP spool 34. Figure 2In the depicted embodiment, the motor 110 is directly operably coupled to the LP spool 34. In other embodiments, the motor 110 may be indirectly coupled to the LP spool 34. For example, the motor 110 may be connected to a shaft that is in turn operably coupled to the LP spool 34. For example, the motor 110 may be operably coupled to a shaft that is operably coupled to the LP spool 34 via a gearbox and / or other speed reduction device.

[0046] The motor 110 includes a rotor 112 and a stator 114. The rotor 112 operably couples the motor 110 with the LP spool 34 and rotates within the stator 114 about an axis of rotation. In some embodiments, the motor 110 may be operated as a motor to drive the LP spool 34 or may be operated as a generator to generate electricity using the rotational energy of the LP spool 34. In other embodiments, the motor 110 may be operated only as a motor. As will be appreciated by those skilled in the art, when the motor 110 is operated as a motor and electricity is directed thereto, the rotor 112 is driven by the interaction between the windings and / or magnetic fields of the rotor 112 and the stator 114. The rotation of the rotor 112 causes the motor 110 to apply torque to the LP spool 34. That is, the rotation of the rotor 112 relative to the stator 114 causes the motor 110 to input electricity to the LP spool 34, so that the rotational speed of the LP spool 34 is changed (e.g., increased). In this way, the rotational speed of the LP spool 34 may be changed (e.g., increased) independently of the second or HP spool 30.

[0047] The control system 100 also includes a power source 116. The motor 110 is in communication with the power source 116, for example, via a power bus 118. The motor 110 is configured to receive power from the power source 116. The power source 116 may be any suitable power source. For example, the power source 116 may be, but is not limited to, one or more energy storage devices (e.g., one or more batteries), a generator operably coupled to another turbine of the aircraft on which the turbofan 10 is installed, an auxiliary power unit (APU) of the aircraft on which the turbofan 10 is installed, some combination thereof, and the like. The power source 116 may be located on the turbofan 10. As an example, the power source 116 may be mounted to the fan case 40 ( Figure 1 As another example, the power supply 116 may be mounted to a nacelle covering the fan housing 40 ( Figure 1 In other embodiments, the power supply 116 may be mounted or positioned outside the turbofan 10. For example, the power supply 116 may be positioned at a suitable location on the aircraft on which the turbofan 10 is mounted, such as a wing or fuselage of the aircraft.

[0048] The control system 100 may include one or more power management electronics or electrical control devices 120, such as inverters, converters, rectifiers, devices operable to control the flow of electrical current, and the like. For example, one or more control devices 120 may be operable to regulate and / or convert electrical power (e.g., from AC to DC or vice versa). Additionally, one or more of the control devices 120 may be operable to control the power provided by the power source 116 to the motor 110. Although in Figure 2 Schematically illustrating that the control device 120 is separated from the power source 116 and the motor 110 , but it should be understood that one, some or all of the control devices 120 may be located on the power source 116 and / or the motor 110 .

[0049] The turbofan 10 includes a computing system. In particular, for this embodiment, the turbofan 10 includes a computing system having one or more computing devices, including a controller 130 configured to control the turbofan 10 and, in this embodiment, the motor 110 and other components of the control system 100. The controller 130 may include one or more processors and associated storage devices configured to perform various computer-implemented functions and / or instructions (e.g., perform methods, steps, calculations, etc. and store related data, as disclosed herein). When executed by the one or more processors, the instructions may cause the one or more processors to perform operations, such as electrically assisting the LP spool 34 during an engine burst or acceleration.

[0050] In addition, the controller 130 may include a communication module to facilitate communication between the controller 130 and various components of the aircraft 200 and other electrical components of the hybrid electric turbofan 10. The communication module may include a sensor interface (e.g., one or more analog-to-digital converters) to allow signals transmitted from one or more sensors to be converted into signals that can be understood and processed by one or more processors. It should be understood that the sensor can be communicatively connected to the communication module using any suitable means. For example, the sensor can be connected to the sensor interface via a wired connection. However, in other embodiments, the sensor can be connected to the sensor interface via a wireless connection (e.g., by using any suitable wireless communication protocol). In this way, the processor can be configured to receive one or more signals or outputs from the sensor, such as one or more operating conditions / parameters.

[0051] As used herein, the term "processor" refers not only to integrated circuits included in computing devices in the art, but also to controllers, microcontrollers, microcomputers, programmable logic controllers (PLCs), application-specific integrated circuits, and other programmable circuits. One or more processors may also be configured to perform the required calculations required to execute advanced algorithms. In addition, the storage device may generally include storage elements, including but not limited to computer-readable media (e.g., random access memory (RAM)), computer-readable non-volatile media (e.g., flash memory), floppy disks, compact disk read-only memories (CD-ROMs), magneto-optical disks (MODs), digital versatile disks (DVDs), and / or other suitable storage elements. Such a storage device may generally be configured to store suitable computer-readable instructions that, when implemented by the processor, configure the controller 130 to perform the various functions described herein. The following references may be used to describe the storage device 130. Fig.14 The controller 130 is configured in substantially the same manner as the exemplary computing device of the described computing system 500 (and the controller 130 may be configured to perform one or more functions of the exemplary method ( 400 ) described herein).

[0052] The controller 130 may be a system of controllers or a single controller. The controller 130 may be a controller dedicated to controlling the motor 110 and associated electrical components, or may be an engine controller configured to control the turbofan 10 as well as the motor 110 and its associated electrical components. The controller 130 may be, for example, an electronic engine controller (EEC) or an electronic control unit (ECU) of a full authority digital engine control (FADEC) system.

[0053] The turbofan 10 also includes one or more sensors for sensing and / or monitoring various engine operating conditions and / or parameters during operation. For example, among other possible locations, one or more sensors 140A may be located at the LP compressor 22, one or more sensors 140B may be located at the HP compressor 24, one or more sensors 140C may be located at the HP turbine 28, and one or more sensors 140D may be located at the LP turbine 32. Sensors 140A, 140B, 140C, 140D may sense or measure various engine conditions, such as pressure and temperature, and one or more signals may be routed from one or more sensors 140A, 140B, 140C, 140D to the controller 130 for processing. Therefore, the controller 130 is connected to the one or more sensors 140A, 140B, 140C, 140D in communication, for example, via a suitable wired or wireless communication link. It should be understood that the turbofan 10 may include other sensors at other suitable locations along the core air flow path.

[0054] The turbofan 10 may also include one or more fuel control devices operable to control the flow of fuel to the turbofan 10 and, more specifically, to the combustion chamber 62 of the combustor 26. For example, Figure 2 1 and 2. Fuel control 150 is shown in FIG. 1 and controls fuel flow to combustor 26. Fuel control 150 is communicatively coupled to controller 130, such as via a suitable wired or wireless communication link.

[0055] Figure 3 A block diagram of a control system 100 operable to control the operation of a hybrid electric turbofan 10 is provided. The hybrid electric turbofan 10 is operable to generate propulsive thrust for an aircraft 200 on which the hybrid electric turbofan 10 is installed. As described above, the control system 100 may include one or more devices, such as sensors, controllers, processors, storage devices, controllable devices, motors, etc., which may monitor and control various aspects of the hybrid electric turbofan 10. In particular, the motor 110 of the control system 100 may be controlled to input power to the LP spool 34, such as during an engine burst. For example, a computing system (e.g., controller 130) may receive input indicating a change in the thrust demand for the hybrid electric turbofan 10, and in response to the received input indicating a change in the thrust demand for the hybrid electric turbofan 10, the computing system may cause the motor 110 to apply torque to the LP spool 34, thereby changing the rotational speed of the LP spool 34. In this way, the motor 110 may electrically assist the turbofan 10 to meet the required thrust. Advantageously, the electric machine 110 can provide electrical assistance during (1) bursts to reduce the HP turbine 28 ( Figure 1 and 2 ) of the rotor expansion; ii) providing electrical assistance during bursts to limit the rate of core speed; and iii) generally providing electrical assistance during engine operation so that the engine can be safely operated close to its stall line, thereby improving engine efficiency and correspondingly reducing fuel burn. The following describes various features of control system 100 and example ways in which electric machine 110 can provide electrical assistance to turbofan 10 to meet the required thrust.

[0056] like Figure 3 As shown, a computing system (e.g., controller 130) of aircraft 200 may receive one or more inputs indicating a change in thrust demand for hybrid electric turbofan 10. The one or more inputs may be in the form of analog or digital electrical signals, for example. The change in thrust demand may be an increase in thrust demand or a decrease in thrust demand. Controller 130 may receive one or more inputs in response to user input or automatically based on commands from a flight control system.

[0057] For example, Figure 3As shown, the aircraft 200 may include one or more thrust input devices 210, such as a power lever or thrust lever that can be moved by a user (e.g., a pilot). By moving the thrust input device 210, the pilot can change (e.g., increase or decrease) the thrust required for the hybrid electric turbofan 10. For example, in order to perform a step climb during cruise operation, the pilot can move the thrust input device 210 to increase the power level and thus increase the thrust demand for the hybrid electric turbofan 10. In this way, the aircraft 200 can better perform step climbs. In some embodiments, one or more thrust input devices 210 may be located outside the aircraft 200, for example, an unmanned aerial vehicle (UAV) of an unmanned aerial vehicle system (UAS) is the case. In addition, in some embodiments, the aircraft 200 may include a flight control system 212 (e.g., an autopilot system) that is operable to automatically change the thrust demand for the hybrid electric turbofan 10.

[0058] The computing system of the aircraft 200 (e.g., the controller 130) may also receive one or more inputs indicative of one or more operating conditions of the hybrid electric turbofan 10 and / or the aircraft 200. The controller 130 may receive one or more inputs from one or more sensors, from control logic that may calculate parameters / conditions based at least in part on received sensor outputs, and / or using one or more models. For example, the controller 130 may receive one or more inputs from the engine sensors 140 (which may include Figure 3 One or more inputs may be received from sensors 140A, 140B, 140C, 140D of the aircraft 200 ), aircraft sensors 214 of the aircraft 200 , and / or aircraft systems 216 of the aircraft 200 (eg, a flight management system).

[0059] Exemplary operating conditions that may be sensed, calculated, and / or modeled include altitude of the aircraft 200, ambient temperature, exhaust temperature, compressor discharge temperature, inlet low pressure compressor temperature, specific fuel consumption, engine efficiency, angle of attack of the aircraft 200, Mach number, thrust, airspeed, fan flow, core flow, current current draw of the motor 110, fan speed, core speed, engine inlet pressure, bypass duct pressure, inlet high pressure compressor pressure, compressor discharge pressure, high pressure turbine pressure, accelerometer measurements, flight control positions, and / or one or more waypoints of a mission (e.g., a start point, an end point, and one or more points between the start point and the end point).

[0060] In some embodiments, as described above, one or more operating conditions may include the altitude at which the hybrid electric turbofan 10 operates, or in other words, the operating conditions may include the altitude of the aircraft 200. The controller 130 may advantageously utilize input indicating the altitude of the aircraft 200 to better determine a thrust demand plan (e.g., fuel input / current input distribution) to control the hybrid electric turbofan 10 during an engine burst. It will be appreciated that, in general, the air density at higher altitudes is less than the air density at lower altitudes, and therefore there is less oxygen in the air at higher altitudes. Therefore, since the motor is not affected by air density, the motor can better compete with the thrust output of the turbine at higher altitudes. In this way, the thrust demand plan can be determined at least in part based on the altitude. For example, at a higher altitude, the motor 110 can be used to meet more thrust requirements than at a lower altitude where the turbofan 10 more effectively meets the thrust requirements. The thrust demand plan can be determined accordingly.

[0061] The computing system of aircraft 200 (eg, controller 130) may also receive one or more inputs indicative of one or more constraints, or more specifically, one or more thrust rate limiting constraints. For example, Figure 3 As shown, the controller 130 may include a high efficiency cruise (HEC) module 160. The HEC module 160 is configured to store a blade tip clearance plan that, when implemented, facilitates efficient cruise operation of the aircraft 200. In particular, when the blade tip clearance plan is implemented, the blade tip clearance may be kept more closed or tighter than otherwise. The HEC module 160 also includes a thrust rate limiting plan that, when implemented, causes the controller 130 to limit the rate of thrust increase of the aircraft 200 during the cruise phase of flight (e.g., due to the relatively tight or closed clearance set by the blade tip clearance plan). In other words, the thrust rate limiting plan, when implemented, prevents the HP spool 30 from accelerating (i.e., increasing rotational speed) beyond a predetermined rate. In this way, the risk of blade tips rubbing against the shroud during step climbs or other acceleration maneuvers during the cruise phase is reduced or eliminated. The thrust rate limiting plan may be received as an input by the controller 130. In some embodiments, the thrust rate limiting schedule forwarded to the controller 130 may be based at least in part on received input indicative of operating conditions of the hybrid-electric turbofan 10 and / or the aircraft 200 .

[0062] In addition to receiving a thrust rate limiting schedule from the HEC module 160, other thrust rate limiting constraints may also be received. For example, the thrust rate limiting constraints may indicate a pressure ratio range within which the hybrid electric turbofan 10 must remain during an acceleration maneuver. In other embodiments, the thrust rate limiting constraints may indicate a stall margin that the hybrid electric turbofan 10 must maintain during an acceleration maneuver.

[0063] For this embodiment, a computing system of the aircraft 200 (eg, the controller 130) includes a thrust requirement planner 170 operable to determine or generate a thrust requirement plan 180 in response to one or more inputs received by the controller 130. In particular, as Figure 4 As shown, the thrust demand plan 180 determined by the thrust demand planner 170 lists a plan for the fuel flow to the turbofan 10 during a time period and a plan for the current flow to the motor 110 during the time period. In other words, the thrust demand plan 180 includes a fuel flow plan 182 and a current plan 184. The thrust demand plan 180 is determined by the thrust demand planner 170 so that when the plan is implemented, the thrust demand is met or substantially met.

[0064] One or more processors of the computing system (e.g., controller 130) may control the flow of fuel to the turbofan 10 during the time period based at least in part on the determined plan for the flow of fuel to the turbofan 10 (i.e., fuel flow plan 182), and may control the flow of current to the motor 110 during the time period based at least in part on the determined plan for the flow of current to the motor 110 (i.e., current plan 184). The fuel flow plan 182 may include one or more fuel flow commands 186, and the current plan 184 may include one or more current commands 188.

[0065] like Figure 3 As shown, fuel flow commands 186 may be routed from controller 130 to fuel control device 150. By routing fuel flow commands 186 to fuel control device 150, controller 130 may cause fuel control device 150 to control fuel flow to turbofan 10 (e.g., combustor 26) based at least in part on one or more fuel flow control commands 186. In other words, fuel control device 150 may control the mass flow rate of fuel flowing downstream from fuel source 152 (e.g., a fuel tank filled with fuel) to combustor 26, thereby ultimately controlling the thrust output of turbofan 10, as increasing the fuel input to turbofan 10 increases the thrust output, while decreasing the fuel input to turbofan 10 decreases the thrust output.

[0066] Similarly, if Figure 3As shown, current commands 188 may be routed from controller 130 to electrical control device 120. By routing current commands 188 to electrical control device 120, controller 130 may cause electrical control device 120 to control current flowing to motor 110 based at least in part on one or more current commands 188. That is, electrical control device 120 may control the amperage of current flowing from power source 116 to motor 110, which ultimately controls the thrust output of turbofan 10. In particular, increased current input to motor 110 increases the torque applied by motor 110 to LP shaft 34, which increases the thrust output of turbofan 10 (assuming all other variables remain constant, such as fuel input). Conversely, decreased current delivered to motor 110 decreases the torque applied by motor 110 to LP shaft 34, which decreases the thrust output of turbofan 10 (assuming all other variables remain the same).

[0067] In some embodiments, the plan 180 is set so that when the plan 180 is implemented, the increase in required thrust is at least partially met by the torque applied by the motor 110 to the LP shaft 34. In other words, in response to the increase in required thrust, the thrust output of the turbofan 10 can be increased at least in part by the motor 110 applying torque on the LP shaft 34. In some embodiments, current can be provided to the motor 110 almost instantaneously in response to the increase in thrust demand. In other embodiments, in response to the increase in thrust demand, current can be provided to the motor 110 at a predefined rate or according to one or more operating conditions or constraints. In addition, in some embodiments, the motor 110 can apply torque on the LP shaft 34 to address a percentage of the increase in thrust demand, and the remaining percentage can be achieved by other means, such as by supplying fuel to the turbofan 10. For example, the motor 110 can be controlled to apply torque on the LP shaft 34 to address fifty percent (50%) of the change in thrust demand, and the remaining percentage can be addressed by increasing the fuel flow to the combustor 26 of the turbofan 10. It should be appreciated that the motor 110 may be controlled to apply torque on the LP shaft 34 to account for any predefined percentage of change in thrust demand.

[0068] In some example embodiments, the plan 180 is set so that when the plan 180 is implemented, one or more processors of the computing system (e.g., the controller 130) initially control the current flowing to the motor 110 so that the motor 110 applies a predefined maximum torque (e.g., the maximum allowable torque that the motor 110 can be operated to output) on the LP shaft 34 to at least partially meet or address the increase in the required thrust. As described above, the predefined maximum torque applied by the motor 110 to the LP shaft 34 can only address a percentage of the increase in thrust demand. For example, the predefined maximum torque applied by the motor 110 to the LP shaft 34 can address seventy-five percent (75%) of the increase in thrust demand. After initially causing the motor 110 to apply the predefined maximum torque or a torque less than the predefined maximum torque on the LP shaft 34, over a period of time (e.g., approximately several seconds), as the fuel input to the turbofan 10 increases (e.g., gradually increases), the pressure applied by the motor 110 to the LP shaft 34 decreases (e.g., decreases in a linear or stepwise manner). In this manner, the turbofan 10 may be more responsive to increases in thrust demand (e.g., due to assistance from the motor 110), may meet or substantially meet increases in thrust demand more quickly than conventional systems, and may maintain thermal matching (i.e., maintain a safe clearance between) between rotating components and adjacent stationary components during thrust changes due to the gradual introduction of fuel over time. Thus, the rotating components are prevented from rubbing against their respective adjacent stationary components.

[0069] In some other example embodiments, the plan 180 is set so that when the plan 180 is implemented, the increase in the required thrust is initially met or substantially met by the torque applied to the LP shaft 34 by the motor 110. The applied torque may be equal to or less than a predefined maximum torque. After the increase in the thrust requirement is initially met or substantially met, the application of the torque applied to the LP shaft 34 by the motor 110 is reduced (e.g., reduced in a linear or stepwise manner) over a period of time as the fuel input to the turbofan 10 increases (e.g., gradually increases). That is, one or more processors of the computing system (e.g., the controller 130) initially control the current flowing to the motor 110 so that the motor 110 applies torque to the LP shaft 34 to address all or nearly all of the increase in the required thrust. Then, the one or more processors of the computing system control the fuel flow to the combustor 26 of the turbofan 10 during the first period of time and control the current flowing to the motor 110 so that during the period of time, the fuel flow to the combustor 26 of the turbofan 10 gradually increases and the current flowing to the motor 110 decreases. In this manner, and in a similar manner as described above, the turbofan 10 may be more responsive to increases in thrust demand (e.g., due to assistance from the motor 110), may meet or substantially meet increases in thrust demand more quickly than conventional systems, and may maintain thermal matching (i.e., maintain a safe gap between) between rotating components and adjacent stationary components during thrust changes due to the gradual introduction of fuel over time. Thus, the rotating components are prevented from rubbing against their respective adjacent stationary components.

[0070] For example, now refer to Figure 3 , 5 , 6 and 7, Figure 5 A graph is provided depicting the thrust demand during a first time period, Figure 6 providing a graph depicting the torque applied by the motor during a first time period, and Figure 7 A graph depicting fuel flow to the turbofan 10 during a first time period is provided. At time t1, the pilot provides user input requesting an increase in thrust. For example, the pilot may provide user input to the thrust input device 210. For example, the pilot may move the thrust input device 210 to request additional thrust, for example, for performing a step climb. In response to the user input, or alternatively, in response to an automatic thrust request, the thrust request planner 170 of the controller 130 receives input indicating an increase in thrust request for the turbofan 10.

[0071] In response to receiving an input indicating an increase in thrust demand for the turbofan 10, one or more processors of the controller 130 cause the motor to apply torque to the LP spool 34, thereby increasing the rotational speed of the LP spool 34. More specifically, the thrust demand planner 170 of the controller 130 determines a thrust demand plan 180 for meeting the increased required thrust or providing a faster response to the increase in thrust demand via assistance from the motor 110. As described above, the thrust demand plan 180 includes a fuel flow plan 182 and a current plan 184. The fuel flow plan 182 includes one or more fuel flow commands 186, which can be routed to the fuel control device 150. The current plan 184 includes one or more current commands 188, which can be routed to the electrical control device 120.

[0072] In addition to inputs indicating an increase in thrust demand for turbofan 10, determined thrust demand schedule 180 may be determined based on one or more operating conditions received from aircraft sensors 214, aircraft systems 216, and engine sensors 140, output from one or more sensors, or otherwise modeled, etc. For example, the altitude of aircraft 200 at time t1 may determine the rate at which fuel is increased and the amperage directed to motor 110 during the first time period. Additionally, determined thrust demand schedule 180 may be determined based on one or more constraints as described above.

[0073] In this example embodiment, one or more processors of controller 130 determine and implement thrust demand schedule 180 such that at or immediately after time t1, motor 110 applies torque to LP shaft 34 to account for the increase in thrust demand. The torque applied by motor 110 to LP shaft 34 may account for all or substantially all of the thrust demand increase or a portion / percent thereof. By utilizing motor 110 to account for at least a portion of the thrust demand increase, the response to the thrust demand is more rapid, thereby providing the pilot with improved feel and control of aircraft 200. Thus, as shown in FIG. Figure 6 As shown, the torque applied by the motor 110 to the LP shaft 34 is rapidly increased to meet the increase in thrust demand at or immediately after time t1. In addition, at time t1, one or more processors of the controller 130 cause an increase in fuel flow to the combustor 26 of the turbofan 10 at a rate not exceeding a predefined rate (e.g., set due to constraints received from the HEC module 160), causing the rotational speed of the HP spool 30 to increase, and more specifically, gradually increase. For example, as Figure 7 As shown, at time t1, fuel is input into the burner 26, and the fuel input gradually increases during the first time period. It is worth noting that as the fuel input increases during the first time period, as shown in FIG. Figure 6As shown, the torque applied by the motor 110 on the LP shaft 34 is reduced or decreased (eg, in a stepwise manner).

[0074] Thus, in this example embodiment, the motor 110 is used to input power to the LP shaft 34 to initially meet or substantially meet the increase in thrust demand. Then, over time, fuel is input at a rate not exceeding a predefined rate (i.e., to prevent a rub event), and the current to the motor 110 is reduced accordingly, so that the thrust demand is eventually fully met by the fuel input without the use of the motor 110. However, it will be appreciated that under certain flight conditions, the motor 110 may continue to assist the turbofan 10 in meeting the required thrust even after a blast event.

[0075] Reference now Figure 3 , 8 , 9 and 10 , provide another example manner in which the motor 110 may electrically assist the hybrid electric turbofan 10 to meet a desired thrust. Figure 8 A graph is provided depicting the thrust demand during a first time period, Fig. 9 providing a graph depicting the torque applied by the motor during a first time period, and Fig.10 A graph depicting fuel flow to turbofan 10 during a first time period is provided. In this example embodiment, generally, in response to an increase in thrust demand, the computing system (e.g., controller 130) causes motor 110 to meet all increases in thrust demand, and in such embodiments, motor 110 may continue to meet increases in thrust demand without any additional fuel input.

[0076] like Figure 8 As shown, the pilot provides a user input requesting an increase in thrust at time t1. For example, the pilot may provide a user input to thrust input device 210. For example, the pilot may move thrust input device 210 to request additional thrust, for example, for performing a step climb during cruise operation. In response to the user input, or alternatively, in response to an automatic thrust request, thrust request planner 170 of controller 130 receives input indicating an increase in thrust request for turbofan 10.

[0077] In response to receiving input indicating an increase in thrust demand on turbofan 10 , one or more processors of controller 130 cause the motor to apply torque to LP spool 34 , thereby increasing the rotational speed of LP spool 34 . Fig. 9As shown, the torque applied by the motor 110 to the LP spool 34 is rapidly increased to meet the increase in thrust demand at or immediately after time t1. More specifically, in response to receiving an input indicating an increase in thrust demand for the turbofan 10, the thrust demand planner 170 of the controller 130 determines a thrust demand plan 180 for meeting the increased required thrust. As described above, the thrust demand plan 180 includes a fuel flow plan 182 and a current plan 184. The fuel flow plan 182 includes one or more fuel flow commands 186, which can be routed to the fuel control device 150. The current plan 184 includes one or more current commands 188, which can be routed to the electrical control device 120.

[0078] As previously described, in addition to inputs indicating an increase in thrust demand for the turbofan 10, the determined thrust demand schedule 180 may be determined based on one or more operating conditions received from the aircraft sensors 214, the aircraft systems 216, the engine sensors 140, calculated from sensor outputs or otherwise modeled, etc. For example, the altitude of the aircraft 200 at time t1 may determine the rate at which fuel is increased and the amperage directed to the motor 110 during the first time period. Additionally, the determined thrust demand schedule 180 may be determined based on one or more constraints as described above.

[0079] In this example embodiment, one or more processors of controller 130 determine and implement thrust demand schedule 180 such that at or immediately after time t1, electric machine 110 applies torque to LP shaft 34 to account for all thrust demand increases. Fig. 9 As shown, the torque applied by the motor 110 to the LP shaft 34 increases rapidly to meet the increase in thrust demand at time t1. However, for this embodiment, the thrust demand schedule 180 is determined and implemented so that no additional fuel is input to the turbofan 10. Therefore, the motor 110 continues to meet the increase in thrust demand without any additional fuel input. Fig.10 As shown, no additional fuel is input to turbofan 10 .

[0080] In some embodiments, particularly during cruise operation, the fuel input may be limited to a predefined fuel input threshold. The predefined fuel input threshold may be received as a constraint by the thrust requirement planner 170. In some embodiments, the predefined fuel input threshold may be set or planned based at least in part on one or more operating conditions of the turbofan 10, the aircraft 200, the motor 110, and / or other electrical components (e.g., the power supply 116). For example, the predefined fuel input threshold may be planned based on, but not limited to, the altitude of the aircraft 200, the electrical energy stored in the power supply 116, the amount of fuel remaining in the fuel source 152, the weight of the aircraft 200, or a combination thereof. In such an embodiment, when the fuel input has reached or is at the predefined fuel input threshold and as Figure 8 As shown, for example, when an increased thrust demand is requested at time t1, the increased thrust demand can be fully or solely met by the motor 110, such as Fig. 9 and 10 When the fuel input drops below a predefined fuel input threshold, fuel may be input to the turbofan 10 (eg, to the combustor 26 ), and the electric machine 110 may be used for electrical assist to meet the increase in thrust demand.

[0081] Fig.11 A schematic diagram of a core turbine engine 14 of another gas turbine engine 10 having a control system 100 is provided according to an example embodiment of the present disclosure. For this embodiment, the gas turbine engine 10 is connected to Figure 1 and 2 The turbofan 10 of FIG. 1 is similarly constructed, except that the motor 110 is operably coupled to the HP spool 30 instead of the LP spool 34. The motor 110 may provide electrical assist to the HP spool 30 in the same or similar manner as the motor 110 described herein provides electrical assist to the LP spool 34.

[0082] Fig.12 A schematic diagram of a core turbine engine 14 of another gas turbine engine 10 having a control system 100 according to an example embodiment of the present disclosure is provided. For this embodiment, the gas turbine engine 10 is coupled to the LP spool 34 except that the first electric machine 110A is operably coupled to the LP spool 34 and the second electric machine 110B is operably coupled to the HP spool 30. Figure 1 and 2 The turbofan 10 of FIG. 1 is constructed similarly. The motors 110A, 110B are constructed in the same or similar manner as the motor 110 described herein. The motor 110A can provide electrical assistance to the LP spool 34 in the same or similar manner as the motor 110 described herein with respect to providing electrical assistance to the LP spool 34, and the motor 110B can provide electrical assistance to the HP spool in the same or similar manner as the motor 110 described herein with respect to providing electrical assistance to the LP spool 34.

[0083] Fig.13 A flow chart of an exemplary method (400) of operating a hybrid electric multi-axis turbine according to an exemplary embodiment of the present disclosure is provided. For example, the exemplary method (400) can be used to operate the hybrid electric turbofan 10 described herein. It should be understood that the method (400) is discussed herein only to describe exemplary aspects of the present subject matter and is not intended to be limiting.

[0084] At (402), the method (400) includes receiving, by one or more computing devices, an input indicating an increase in thrust demand for a multi-spool turbine having a first rotatable component and a second rotatable component, such as a first spool and a second spool, respectively. For example, the controller 130 may receive the input in response to a user input (e.g., movement of the thrust input device 210) or automatically based on a command from the flight control system 212. In some embodiments, the multi-spool turbine may have more than two spools.

[0085] At (404), in response to receiving input indicating an increase in thrust demand for the multi-spool turbine, the method (400) includes causing, by one or more computing devices, a motor operably coupled to a first spool to increase a rotational speed of the first spool. Figure 2 As shown, controller 130 may cause electrical control device 120 to direct current from power source 116 to motor 110. The current causes motor 110 to apply torque to LP shaft 34, thereby increasing the rotational speed of LP shaft 34. In some embodiments, motor 110 applies torque to LP spool 34, causing the rotational speed of LP spool 34 to increase independently of HP spool 30 or any other spool of turbofan 10.

[0086] In some embodiments, the motor 110 can apply torque to the LP shaft 34 almost instantaneously in response to an increase in the required thrust. In addition, in response to the thrust demand, one or more computing devices can cause fuel to flow to the combustor 26 of the multi-spool turbofan 10. For example, Figure 7 As shown, the fuel flow to the burner 26 may be increased or gradually increased during the first time period. In addition, after the motor 110 increases the speed of the LP spool 34 via one or more computing devices, the one or more computing devices may decrease the current flowing to the motor 110 during the first time period, for example, Figure 6 As shown. Figure 7 As the fuel input increases, the current flowing to the motor 110 can be gradually reduced, such as Figure 6 Thus, the engine responds to increases in thrust demand due to the electrical assistance provided by the electric machine 110, and the rotating and stationary components of the engine remain thermally matched without experiencing friction events.

[0087] In some embodiments, in response to receiving an input indicating an increase in thrust demand for the multi-spool turbine, the motor 110 may apply torque to the LP spool 34 such that the increase in thrust demand is met or substantially met. Thereafter, the motor 110 may continue to apply torque to the LP spool 34 to meet the increased demanded thrust, e.g., Fig. 9 In such an embodiment, no additional fuel is required to be input to the turbofan 10 because the motor 110 provides all the additional thrust required to meet the thrust demand. In this way, the fuel input can be maintained below the fuel input threshold, for example, Fig.10 This embodiment may be particularly useful at high altitudes, such as 25,000 feet and above.

[0088] Fig.14 An example computing system 500 is provided according to an example embodiment of the present disclosure. For example, the computing system described herein (eg, controller 130) may include various components and perform various functions of the computing system 500 described below.

[0089] like Fig.14 As shown, the computing system 500 may include one or more computing devices 510. The computing device 510 may include one or more processors 510A and one or more storage devices 510B. The one or more processors 510A may include any suitable processing device, such as a microprocessor, a microcontroller, an integrated circuit, a logic device, and / or other suitable processing device. The one or more storage devices 510B may include one or more computer-readable media, including but not limited to non-transitory computer-readable media, RAM, ROM, hard disk drives, flash drives, and / or other storage devices.

[0090] The one or more storage devices 510B may store information accessible by the one or more processors 510A, including computer readable instructions 510C that may be executed by the one or more processors 510A. The instructions 510C may be any set of instructions that, when executed by the one or more processors 510A, cause the one or more processors 510A to perform operations. In some embodiments, the instructions 510C may be executed by the one or more processors 510A to cause the one or more processors 510A to perform operations, such as any operations and functions for which the computing system 500 and / or computing device 510 are configured, operation of an electrically assisted turbine during transient operation (e.g., method (400)), and / or any other operation or function of the one or more computing devices 510. Thus, the method (400) may be a computer-implemented method such that each step of the exemplary method (400) is performed by one or more computing devices (such as the exemplary computing device 510 of the computing system 500). The instructions 510C may be software written in any suitable programming language, or may be implemented in hardware. Additionally, and / or alternatively, the instructions 510C may be executed in a logically and / or virtually separate thread on the processor 510A. The storage device 510B may further store data 510D that may be accessed by one or more processors 510A. For example, the data 510D may include models, databases, etc.

[0091] The computing device 510 may also include a network interface 510E for communicating with other components of the system 500 (e.g., via a network), for example. The network interface 510E may include any suitable components for interfacing with one or more networks, including, for example, transmitters, receivers, ports, controllers, antennas, and / or other suitable components. One or more external devices, such as the fuel control device 150 and the electrical control device 120, may be configured to receive one or more commands from the computing device 510 or to provide one or more commands to the computing device 510.

[0092] FIG. 15 provides an example vehicle 600 according to an example embodiment of the present disclosure. The hybrid electric turbine and method of the present disclosure may be implemented on an aircraft, a helicopter, an automobile, a ship, a submarine, a train, an unmanned aerial vehicle or a drone and / or on any other suitable vehicle. Although the present disclosure is described herein with reference to an aircraft embodiment, this is intended to be used as an example only and not limiting. One of ordinary skill in the art will appreciate that the hybrid electric turbine and method of the present disclosure may be implemented on other vehicles without departing from the scope of the present disclosure.

[0093] The techniques discussed herein refer to computer-based systems and actions taken by computer-based systems and information sent from and to computer-based systems. One of ordinary skill in the art will recognize that the inherent flexibility of computer-based systems allows for a variety of possible configurations, combinations, and divisions of tasks and functions between and among components. For example, a single computing device or multiple computing devices working in combination may be used to implement the processing discussed herein. Databases, memories, instructions, and applications may be implemented on a single system or distributed across multiple systems. Distributed components may operate sequentially or in parallel.

[0094] Although specific features of various embodiments may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the present disclosure, any feature of a drawing may be referenced and / or claimed in combination with any feature of any other drawing.

[0095] This written description uses examples to disclose the invention, including the best mode, and also to enable those skilled in the art to practice the invention, including making and using any device or system and performing any combined method. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. If such other examples include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims, then these other examples are intended to be included within the scope of the claims.

[0096] Further aspects of the invention are provided by the subject matter of the following clauses:

[0097] 1. A vehicle, comprising: a gas turbine engine, the gas turbine engine comprising: a first rotatable component; a second rotatable component; an electric motor, the electric motor being operably coupled to the first rotatable component and in communication with a power source, the electric motor being operable to receive power from the power source; a computing system, the computing system having one or more processors and one or more storage devices, the one or more storage devices storing instructions, the instructions causing the one or more processors to perform operations when executed by the one or more processors, when performing the operations, the one or more processors being configured to: receive an input indicating a change in thrust demand for the gas turbine engine; and in response to the received input indicating a change in thrust demand for the gas turbine engine, causing the electric motor to change an applied torque on the first rotatable component, thereby changing a rotational speed of the first rotatable component.

[0098] 2. A vehicle according to any preceding clause, wherein the first rotatable element is a low voltage spool and the second rotatable element is a high voltage spool.

[0099] 3. A vehicle according to any preceding clause, wherein the first rotatable element is a high voltage spool and the second rotatable element is a low voltage spool.

[0100] 4. A vehicle according to any preceding clause, wherein the change in thrust demand for the gas turbine engine is a reduction in thrust demand for the gas turbine engine, and wherein, when the one or more processors cause the motor to change the applied torque on the first rotatable component, the motor reduces the applied torque on the first rotatable component, or causes the motor to apply a drag torque on the first rotatable component, thereby reducing the rotational speed of the first rotatable component.

[0101] 5. A vehicle according to any preceding clause, wherein the change in thrust demand for the gas turbine engine is an increase in thrust demand for the gas turbine engine, and wherein, when the one or more processors cause the motor to change the applied torque on the first rotatable component, the motor increases the applied torque on the first rotatable component, thereby increasing the rotational speed of the first rotatable component.

[0102] 6. A vehicle according to any preceding clause, wherein, in response to received input indicating a change in thrust demand for the gas turbine engine, one or more processors are configured to: increase the flow of fuel to the gas turbine engine at a rate not exceeding a predefined rate, thereby increasing the rotational speed of the second rotatable component.

[0103] 7. A vehicle according to any preceding clause, wherein one or more processors are configured to: determine a thrust demand plan based at least in part on received input indicating a change in thrust demand for the gas turbine engine to meet the thrust demand over time, the thrust demand plan comprising a plan for fuel flow to the gas turbine engine over time and a plan for current flow to the motor over time, and wherein the one or more processors: i) control the fuel flow to the gas turbine engine over time based at least in part on the determined plan for fuel flow to the gas turbine engine over time; and ii) control the current flow to the motor over time based at least in part on the determined plan for current flow to the motor over time.

[0104] 8. A vehicle according to any preceding clause, wherein the one or more processors are configured to: receive inputs indicative of one or more operating conditions of the gas turbine engine, and wherein the thrust demand plan is determined by the one or more processors based at least in part on the inputs indicative of one or more operating conditions of the gas turbine engine.

[0105] 9. A vehicle according to any preceding clause, wherein the one or more operating conditions of the gas turbine engine include at least one of an altitude at which the gas turbine engine is operating, an airspeed of the vehicle and an ambient temperature external to the vehicle.

[0106] 10. A vehicle according to any preceding clause, wherein the gas turbine engine further comprises a fuel control device operable to control a flow of fuel to the gas turbine engine, the fuel control device being communicatively coupled to the computing system, and wherein the vehicle further comprises a current control device operable to control a flow of current to the motor, the current control device being communicatively coupled to the computing system, and wherein the schedule of the flow of fuel to the gas turbine engine over time comprises one or more fuel flow commands, and the schedule of the current to the motor over time comprises one or more current commands, and wherein, in controlling the flow of fuel to the gas turbine over time based at least in part on the determined schedule of the flow of fuel to the gas turbine engine over time, the one or more processors are configured to cause the fuel control device to control the flow of fuel to the gas turbine engine based at least in part on the one or more fuel flow control commands, and wherein, in controlling the current to the motor over time based at least in part on the determined schedule of the current to the motor over time, the one or more processors are configured to cause the current control device to control the current to the motor based at least in part on the one or more current control commands.

[0107] 11. A vehicle according to any of the preceding clauses, wherein one or more processors control the flow of fuel to the gas turbine engine over time and control the current flowing to the motor over time, such that the flow of fuel to the gas turbine engine gradually increases over time and the current flowing to the motor decreases over time.

[0108] 12. A turbine for a vehicle, comprising: a first rotatable component; a second rotatable component; a motor, the motor being operably connected to the first rotatable component; and a controller, the controller having one or more processors and one or more storage devices, the one or more storage devices storing instructions, the instructions when executed by the one or more processors causing the one or more processors to perform operations, when performing the operations, the one or more processors being configured to: receive input indicating an increase in thrust demand for the turbine; and in response to the increase in thrust demand for the turbine, cause the motor to apply torque to the first rotatable component.

[0109] 13. A turbine according to any preceding clause, wherein the first rotatable element is a low pressure spool and the second rotatable element is a high pressure spool.

[0110] 14. A turbine according to any preceding clause, wherein the first rotatable element is a high pressure spool and the second rotatable element is a low pressure spool.

[0111] 15. A turbine according to any preceding clause, wherein the one or more processors of the controller are configured to: increase the flow of fuel to the turbine such that the rotational speed of the second rotatable element increases.

[0112] 16. A turbine according to any of the preceding clauses, wherein one or more processors of the controller controls an increase in fuel flow to the turbine during a first time period, and controls a current flowing to the motor during the first time period, so that the fuel flow to the turbine gradually increases during the first time period, and the current flowing to the motor decreases during the first time period.

[0113] 17. A turbine according to any preceding clause, wherein one or more processors of the controller are configured to: receive an input indicating a constraint describing a fuel input threshold, and wherein, when the fuel flow to the turbine reaches the fuel input threshold, an increase in thrust demand is met solely by the application of torque applied by the electric machine to the first rotatable component.

[0114] 18. A method comprising: receiving, by one or more computing devices, an input indicating an increase in thrust demand for a multi-spool turbine having a first spool and a second spool; and in response to the received input indicating an increase in thrust demand for the multi-spool turbine, causing, by the one or more computing devices, a motor operably coupled to a first spool to increase a rotational speed of the first spool.

[0115] 19. A method according to any of the preceding clauses, wherein causing the motor to increase the rotational speed of the first spool by one or more computing devices comprises causing the motor to apply torque to the first spool by one or more computing devices so that the rotational speed of the first spool increases independently of the rotational speed of the second spool.

[0116] 20. A method according to any of the preceding clauses, wherein causing a motor operably connected to a first spool to increase the rotational speed of the first spool by one or more computing devices comprises: causing the motor to increase the rotational speed of the first spool by one or more computing devices so that thrust requirements are substantially met, and wherein the method further comprises: causing a fuel flow to flow to a combustor of a multi-spool turbine by one or more computing devices, wherein the fuel flow to the combustor gradually increases within a first time period; and after causing the motor to increase the rotational speed of the first spool by one or more computing devices so that thrust requirements are substantially met, causing the current flowing to the motor to decrease within the first time period by one or more computing devices.

Claims

1. A carrier, characterized in that: include: A gas turbine engine, the gas turbine engine comprising: a first rotatable member; a second rotatable member; an electric motor operably coupled to the first rotatable member and in communication with a power source, the electric motor being operable to receive power from the power source; A computing system having one or more processors and one or more storage devices, wherein the one or more storage devices store instructions that, when executed by the one or more processors, cause the one or more processors to perform operations, wherein when performing the operations, the one or more processors are configured to: receiving input indicative of a change in thrust demand for the gas turbine engine; causing the electric machine to vary the applied torque on the first rotatable component, thereby varying the rotational speed of the first rotatable component, in response to receiving an input indicative of a change in the thrust demand for the gas turbine engine; and receiving input indicating a constraint describing a fuel input threshold, and Therein, when fuel flow to the gas turbine engine reaches the fuel input threshold, an increase in thrust demand is met solely by application of torque applied by the electric machine to the first rotatable component.

2. The carrier according to claim 1, characterized in that in, The first rotatable element is a low voltage spool and the second rotatable element is a high voltage spool.

3. The carrier according to claim 1, characterized in that in, The first rotatable element is a high voltage spool and the second rotatable element is a low voltage spool.

4. The carrier according to claim 1, characterized in that in, The change in thrust demand for the gas turbine engine is a reduction in the thrust demand for the gas turbine engine, and wherein, when the one or more processors cause the electric motor to change the applied torque on the first rotatable component, the electric motor reduces the applied torque on the first rotatable component or causes the electric motor to apply a drag torque on the first rotatable component, thereby reducing the rotational speed of the first rotatable component.

5. The carrier according to claim 1, characterized in that in, The change in thrust demand for the gas turbine engine is an increase in the thrust demand for the gas turbine engine, and wherein, when the one or more processors cause the electric machine to change the applied torque on the first rotatable component, the electric machine increases the applied torque on the first rotatable component, thereby increasing the rotational speed of the first rotatable component.

6. The carrier according to claim 5, characterized in that in, In response to the received input indicating a change in the thrust demand for the gas turbine engine, the one or more processors are configured to: Fuel flow to the gas turbine engine is increased at a rate not exceeding a predefined rate, thereby increasing the rotational speed of the second rotatable component.

7. The carrier according to claim 1, characterized in that in, The one or more processors are configured to: determining a thrust demand plan to meet the thrust demand over time based at least in part on the received input indicative of a change in the thrust demand for the gas turbine engine, the thrust demand plan comprising a plan for fuel flow to the gas turbine engine over time and a plan for current flow to the electric machine over time, and wherein the one or more processors: i) controlling fuel flow to the gas turbine engine over time based at least in part on the determined plan of fuel flow to the gas turbine engine over time; and ii) controlling current to the electric machine over time based at least in part on the determined schedule of current to the electric machine over time.

8. The carrier according to claim 7, characterized in that in, The one or more processors are configured to: receiving input indicative of one or more operating conditions of the gas turbine engine, and Wherein the thrust demand plan is determined by the one or more processors based at least in part on the input indicative of the one or more operating conditions of the gas turbine engine.

9. The carrier according to claim 8, characterized in that in, The one or more operating conditions of the gas turbine engine include at least one of an altitude at which the gas turbine engine is operating, an airspeed of the vehicle, and an ambient temperature external to the vehicle.

10. The carrier according to claim 7, characterized in that in, The gas turbine engine further includes a fuel control device operable to control a flow of fuel to the gas turbine engine, the fuel control device being communicatively coupled to the computing system, and The vehicle further comprises a current control device operable to control the current flowing to the motor, the current control device being communicatively coupled to the computing system, and wherein the plan of fuel flow to the gas turbine engine over time comprises one or more fuel flow commands, and the plan of current flow to the electric machine over time comprises one or more current commands, and wherein, when controlling the flow of fuel to the gas turbine over time based at least in part on the determined plan of fuel flow to the gas turbine engine over time, the one or more processors are configured to cause the fuel control device to control the flow of fuel to the gas turbine engine based at least in part on the one or more fuel flow control commands, and Wherein, while controlling the current flowing to the motor over time based at least in part on a determined plan of the current flowing to the motor over time, the one or more processors are configured to cause the current control device to control the current to the motor based at least in part on the one or more current control commands.

11. The carrier according to claim 7, characterized in that in, The one or more processors control fuel flow to the gas turbine engine over time and control current flow to the motor over time such that fuel flow to the gas turbine engine gradually increases over time and current flow to the motor decreases over time.

12. A turbine for a vehicle, characterized in that: include: a first rotatable member; a second rotatable member; a motor operably coupled to the first rotatable member; and A controller having one or more processors and one or more storage devices, wherein the one or more storage devices store instructions, which when executed by the one or more processors cause the one or more processors to perform operations, wherein when performing the operations, the one or more processors are configured to: receiving an input indicative of an increase in thrust demand on the turbine; and causing the electric machine to apply torque to the first rotatable member in response to the thrust demand on the turbine increasing; receiving input indicating a constraint describing a fuel input threshold, and Therein, when fuel flow to the turbine reaches the fuel input threshold, an increase in thrust demand is met solely by application of torque applied by the electric machine to the first rotatable component.

13. The turbine according to claim 12, characterized in that in, The first rotatable element is a low voltage spool and the second rotatable element is a high voltage spool.

14. The turbine according to claim 12, characterized in that in, The first rotatable element is a high voltage spool and the second rotatable element is a low voltage spool.

15. The turbine according to claim 12, characterized in that in, The one or more processors of the controller are configured to: Fuel flow to the turbine is increased so that the rotational speed of the second rotatable element increases.

16. The turbine according to claim 15, characterized in that in, The one or more processors of the controller control an increase in the fuel flow to the turbine during a first time period, and control an electric current flowing to the motor during the first time period, so that the fuel flow to the turbine gradually increases during the first time period, and the electric current flowing to the motor decreases during the first time period.

17. A method of operating a turbine, characterized in that include: receiving, by one or more computing devices, input indicating an increase in thrust demand for a multi-spool turbine having a first spool and a second spool; In response to the received input indicating an increase in the thrust demand for the multi-spool turbine, causing, by the one or more computing devices, an electric motor operably coupled to the first spool to increase a rotational speed of the first spool; receiving, by one or more processors, input indicative of a constraint describing a fuel input threshold, and Therein, when the fuel flow to the turbine reaches the fuel input threshold, an increase in thrust demand is met solely by application of torque applied by the electric machine to the first spool.

18. The method according to claim 17, characterized in that in, Causing the motor, by the one or more computing devices, to increase the rotational speed of the first spool includes causing the motor, by the one or more computing devices, to apply torque to the first spool such that the rotational speed of the first spool increases independently of the second spool.

19. The method according to claim 18, characterized in that in, Causing the motor operably coupled to the first spool to increase the rotational speed of the first spool by the one or more computing devices includes: causing the motor to increase the rotational speed of the first spool by the one or more computing devices so that the thrust requirement is substantially met, and wherein the method further comprises: causing, by the one or more computing devices, a flow of fuel to a combustor of the multi-spool turbine, wherein the flow of fuel to the combustor gradually increases over a first time period; and After the one or more computing devices cause the motor to increase the rotational speed of the first spool so that the thrust demand is substantially met, the one or more computing devices cause the current flowing to the motor to be reduced within the first time period.

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