Systems and methods for efficiently determining phase shifts in propulsion systems

Abstract

A propulsion system includes at least two propellers. The at least two propellers each include a fan having a plurality of fan blades. The controller includes a memory and one or more processors. The memory stores instructions that, when executed by the one or more processors, cause the system to: determine a pairwise phase difference between one of the at least two thrusters and another of the at least two thrusters; generating a reference phase angle; determining a target phase shift for each of the at least two propellers; and adjusting the speed of each of the at least two propellers based on the target phase shift until the pairwise phase difference equals the reference phase angle.

Description

Technical Field

[0001] The present subject matter generally relates to systems and methods for determining an effective phase shift in a propulsion system to synchronize phase angles between thrusters in the propulsion system. Background Art

[0002] Conventional commercial aircraft generally include a fuselage, a pair of wings, and a propulsion system that provides thrust. The propulsion system generally includes at least two aircraft engines, such as turbofan jet engines. Each turbofan jet engine is generally mounted to a corresponding one of the wings of the aircraft, such as in a hanging position below the wing, separate from the wing and the fuselage.

[0003] In aircraft with two or more engines (i.e., multi-engine aircraft), phase angle refers to the position of the fan blades on each engine relative to each other. When the fan blades of an engine are not optimally phase-shifted relative to each other, or when the engines are not rotating at the same speed, it can result in an uneven application of power and torque, leading to vibration and noise. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] A full and enabling disclosure of the present disclosure, including the best mode thereof, to one of ordinary skill in the art is set forth in the specification with reference to the accompanying drawings, in which:

[0005] Figure 1 is a top view of an aircraft according to various exemplary embodiments of the present disclosure.

[0006] Figure 2 yes Figure 1 A side view of an exemplary aircraft.

[0007] Figure 3 is a schematic cross-sectional view of a gas turbine engine according to an exemplary embodiment of the present disclosure, which gas turbine engine may be mounted to Figure 1 An exemplary aircraft.

[0008] Figure 4 is a schematic diagram of a propulsion system according to an exemplary embodiment of the present disclosure.

[0009] Figure 5 is a front view of an aircraft having a propulsion system with two thrusters according to an embodiment of the present disclosure.

[0010] Figure 6 is a front view of an aircraft having a propulsion system with four thrusters according to an embodiment of the present disclosure.

[0011] Figure 7 is a flow chart of a method of operating a propulsion system according to an embodiment of the present disclosure.

[0012] Figure 8 A block diagram of a computing system for implementing one or more aspects of the present disclosure is provided according to an example embodiment of the present disclosure. DETAILED DESCRIPTION

[0013] Reference will now be made in detail to the present embodiments of the present disclosure, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter references to refer to features in the drawings. Like or similar reference numbers in the drawings and description have been used to refer to like or similar parts of the present disclosure.

[0014] The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations. In addition, unless expressly stated otherwise, all embodiments described herein should be considered exemplary.

[0015] The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0016] The term "at least one" in a context such as "at least one of A, B, and C" means only A, only B, only C, or any combination of A, B, and C.

[0017] 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 position or importance of each component.

[0018] The terms "front" and "rear" refer to relative positions within a gas turbine engine or vehicle, and refer to the normal operating attitude of the gas turbine engine or vehicle. For example, with respect to a gas turbine engine, front refers to a position closer to the engine inlet, while rear refers to a position closer to the engine nozzle or exhaust.

[0019] The terms "upstream" and "downstream" refer to relative directions with respect to flow in a path. For example, with respect to fluid flow, "upstream" refers to the direction from which the fluid is flowing, and "downstream" refers to the direction toward which the fluid is flowing. However, the terms "upstream" and "downstream" as used herein may also refer to electrical current.

[0020] As used herein throughout the specification and claims, approximate language is applied to modify any quantitative representation that allows variation without causing a change in the basic function associated therewith. Therefore, the values ​​modified by terms such as "about", "approximately" and "substantially" are not limited to the specified exact values. In at least some cases, approximate language may correspond to the accuracy of an instrument for measuring a value, or the accuracy of a method or machine for constructing or manufacturing a component and / or system. In at least some cases, approximate language may correspond to the accuracy of an instrument for measuring a value, or the accuracy of a method or machine for constructing or manufacturing a component and / or system. For example, approximate language may refer to within a margin of 1%, 2%, 4%, 5%, 10%, 15% or 20% of a single value, a range of values ​​and / or an endpoint of a limited range of values.

[0021] Here and throughout the specification and claims, range limitations are combined and interchanged, and unless context or language indicates otherwise, such ranges are identified and include all sub-ranges contained therein. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other.

[0022] In aircraft with two or more engines (i.e., multi-engine aircraft), phase angle refers to the position of the fan blades on each engine relative to each other. When the fan blades of an engine are not optimally phase-shifted relative to each other, or when the engines are not rotating at the same speed, uneven application of power and torque can result, causing vibration and noise.

[0023] The present disclosure provides various control methods for generating optimized synchrophasing reference signals to allow a multi-engine propulsion system to synchronize the speed and / or phase angle between fan blades. The synchrophasing reference signals can be generated for each engine in the multi-engine propulsion system at least in part by minimizing or otherwise reducing a cost function. As a result, each engine in the multi-engine propulsion system can be independently adjusted (e.g., speed adjusted) according to the synchrophasing reference signals, thereby facilitating synchronization of the speed and phase angle between the fan blades in an efficient manner.

[0024] In addition, for a hybrid electric gas turbine engine, the motor can be coupled to one or both of the high pressure system and the low pressure system, such as coupled to a shaft that can rotate with the high pressure system and / or the low pressure system. The present disclosure utilizes a motor to facilitate synchronization of the phase angle and / or blade speed of one or more engines in an aircraft. That is, the motor can be used to apply, extract, or transfer power to the fan and / or propeller shaft of the aircraft engine to achieve synchronization of the speed and / or blade phase from one or more engines to another engine. The use of an embedded motor for synchronous phasing advantageously allows phase errors to be eliminated more quickly with minimal interference to engine performance or control, and can be applied and coordinated on multiple propeller engines that are fuel-driven or electrically driven.

[0025] Referring now to the drawings, in which like numerals represent like elements throughout, Figure 1 A schematic top view of an aircraft 10 having a hybrid electric propulsion system 50 according to another exemplary embodiment of the present disclosure is provided. Figure 2 Provided Figure 1 In particular, Figure 1 and Figure 2 An aircraft 10 is shown defining a longitudinal centerline 14 extending therethrough, a lateral direction L, a front end 16, and a rear end 18. The aircraft 10 includes a fuselage 12, a tail 19, a first wing 20, and a second wing 22. The first wing 20 and the second wing 22 each extend laterally outward relative to the longitudinal centerline 14. The first wing 20 and a portion of the fuselage 12 together define a first side 24 of the aircraft 10, and the second wing 22 and another portion of the fuselage 12 together define a second side 26 of the aircraft 10. For the depicted embodiment, the first side 24 of the aircraft 10 is configured as the port side of the aircraft 10, and the second side 26 of the aircraft 10 is configured as the starboard side of the aircraft 10.

[0026] Each of the wings 20, 22 of the depicted exemplary embodiment includes one or more leading edge flaps 28 and one or more trailing edge flaps 30. The aircraft 10 also includes, or more precisely, the tail 19 of the aircraft 10 includes: a vertical stabilizer 32, which has a rudder flap (not shown) for yaw control; and a pair of horizontal stabilizers 34, each of which has an elevator flap 36 for pitch control. The fuselage 12 additionally includes an outer surface or skin 38. However, it should be understood that in other exemplary embodiments of the present disclosure, the aircraft 10 may additionally or alternatively include any other suitable configuration. For example, in other embodiments, the aircraft 10 may include any other configuration of stabilizers.

[0027] Figure 1The exemplary aircraft 10 also includes a hybrid electric propulsion system 50 having a first gas turbine engine 100A, a second gas turbine engine 100B, and an electrical energy storage unit 57. For the depicted embodiment, the first gas turbine engine 100A and the second gas turbine engine 100B are each configured in an underwing mounted configuration. Figure 1 Only an aircraft with two gas turbine engines is depicted, but the aircraft 10 may have any number of gas turbine engines, such as one per wing, two per wing, three per wing, or any other number of gas turbine engines.

[0028] Now also refer to Figure 3 , a schematic cross-sectional view of a gas turbine engine 100 is provided. Figure 1 and Figure 2 The first and second gas turbine engines 100A, 100B depicted in FIG. 1 may be configured to operate in a manner similar to that of FIG. Figure 3 The exemplary engine 100 is constructed in a similar manner.

[0029] Figure 3 The gas turbine engine 100 is more specifically configured as a turbofan engine 100 including a turbine 102 and a fan 104. Figure 3 As shown, turbofan engine 100 defines an axial direction A (extending parallel to a longitudinal centerline 101 for reference) and a radial direction R. As described above, turbofan engine 100 includes a fan 104 and a turbine 102 disposed downstream of fan 104 .

[0030] The depicted exemplary turbomachine 102 generally includes a substantially tubular casing 106 defining an annular inlet 108. The casing 106 encloses, in serial flow relationship: a compressor section including a supercharger or low pressure (LP) compressor 110 and a high pressure (HP) compressor 112; a combustion section 114; a turbine section including a first high pressure (HP) turbine 116 and a second low pressure (LP) turbine 118; and an ejection exhaust nozzle section 120. The compressor section, combustion section 114, and turbine section together at least partially define a core air flow path 121.

[0031] The exemplary turbine 102 of the turbofan engine 100 also includes one or more shafts that can rotate with at least a portion of the turbine section and, for the depicted embodiment, can rotate with at least a portion of the compressor section. More specifically, for the depicted embodiment, the turbofan engine 100 includes a high pressure (HP) shaft or spool 122 that drivingly connects the HP turbine 116 to the HP compressor 112. Additionally, the exemplary turbofan engine 100 includes a low pressure (LP) shaft or spool 124 that drivingly connects the LP turbine 118 to the LP compressor 110.

[0032] In addition, the depicted exemplary fan 104 is configured as a variable pitch fan having a plurality of fan blades 128 coupled to a disk 130 in a spaced apart manner. The fan blades 128 extend outwardly from the disk 130 generally along a radial direction R. Each fan blade 128 can rotate relative to the disk 130 about a respective pitch axis P by virtue of the fan blades 128 being operably coupled to appropriate actuating members 132, the actuating members 132 being configured to collectively change the pitch of the fan blades 128. The fan 104 is mechanically coupled to the LP shaft 124 such that the fan 104 is mechanically driven by the second LP turbine 118. More specifically, the fan 104 including the fan blades 128, the disk 130, and the actuating members 132 is mechanically coupled to the LP shaft 124 through a power gearbox 134, and can rotate about the longitudinal axis 101 across the power gearbox 134 through the LP shaft 124. The power gearbox 134 includes a plurality of gears for reducing the rotational speed of the LP shaft 124 to a more efficient rotating fan speed. Thus, the fan 104 is powered by the LP system of the turbomachine 102 , including the LP turbine 118 .

[0033] Still reference Figure 3 In an exemplary embodiment of the present invention, the disk 130 is covered by a rotatable front hub 136, which is aerodynamically shaped to facilitate airflow through the plurality of fan blades 128. In addition, the turbofan engine 100 includes an annular fan case or outer nacelle 138 circumferentially surrounding the fan 104 and / or at least a portion of the turbine 102. Therefore, the exemplary turbofan engine 100 depicted can be referred to as a "ducted" turbofan engine. In addition, the nacelle 138 is supported relative to the turbine 102 by a plurality of circumferentially spaced outlet guide vanes 140. A downstream section 142 of the nacelle 138 extends over an outer portion of the turbine 102 so as to define a bypass airflow passage 144 therebetween.

[0034] Still reference Figure 3, the hybrid electric propulsion system 50 also includes an electric motor 56, which, for the depicted embodiment, can be configured as an electric motor / generator. For the depicted embodiment, the electric motor 56 is positioned within the turbine 102 of the turbofan engine 100 and is mechanically connected to one of the shafts of the turbofan engine 100. More specifically, for the depicted embodiment, the electric motor 56 is a first electric motor 56-1, and is positioned inside the core air flow path 121, driven by the first HP turbine 116 through the HP shaft 122. The first electric motor 56-1 is configured to convert the mechanical power of the HP shaft 122 into electrical power during certain operations, and is further configured to convert electrical power into mechanical power in other operations. Therefore, the first electric motor 56-1 can be powered by the HP system (including the HP turbine 116) of the turbine 102 during certain operations, and can power the HP system during other operations.

[0035] In addition, for the described embodiment, the hybrid electric propulsion system 50 also includes a second electric machine 56-2. The second electric machine 56-2 is configured to convert the mechanical power of the LP shaft 124 into electrical power during certain operations, and is further configured to convert the electrical power into mechanical power during other operations. Therefore, the second electric machine 56-2 can be powered by the LP system (including the LP turbine 118 and the fan 104) of the turbomachine 102 during certain operations, and can provide power to the LP system during other operations.

[0036] It is worth noting that the motors 56-1, 56-2 can be relatively powerful motor / generators. For example, in some embodiments, during certain operations, the motors 56-1, 56-2 can be configured to generate at least about fifty kilowatts of electrical power or at least about sixty-five horsepower of mechanical power. In other embodiments, the motors 56-1, 56-2 can be configured to generate up to two hundred kilowatts of electrical power. However, in other embodiments, the motors 56-1, 56-2 can generate other amounts of power.

[0037] However, it should be understood that in other exemplary embodiments, the motors 56-1, 56-2 may alternatively be positioned at any other suitable location or other location within the turbine 102, and may be powered, for example, in any other suitable manner. For example, in other embodiments, the first motor 56-1 may be mounted within the turbine section coaxially with the HP shaft 122, or alternatively may be offset from the HP shaft 122 and driven by a suitable gear train. Similarly, in other embodiments, the second motor 56-2 may be mounted within the compressor section coaxially with the LP shaft 124, or alternatively may be offset from the LP shaft 124 and driven by a suitable gear train. Additionally or alternatively, in still other embodiments, the hybrid electric propulsion system 50 may not include the first and second motors 56-1, 56-2, but may include only one of such motors 56-1 and 56-2.

[0038] It should be further understood that in other exemplary embodiments, Figure 3 The exemplary turbofan engine 100 depicted in the figure may have any other suitable configuration. For example, in other exemplary embodiments, the fan 104 may not be a variable pitch fan, and further, in other exemplary embodiments, the LP shaft 124 may be directly mechanically coupled to the fan 104 (i.e., the turbofan engine 100 may not include a gearbox 134). In addition, it should be understood that in other exemplary embodiments, the first propeller 52 may include any other suitable type of engine. For example, in other embodiments, the turbofan engine 100 may alternatively be configured as a turboprop engine or a non-ducted turbofan engine. In addition, in other embodiments, the turbofan engine 100 may alternatively be configured as any other suitable combustion engine for driving motors 56-1, 56-2. For example, in other embodiments, the turbofan engine may be configured as a turboshaft engine, or any other suitable combustion engine (such as a non-ducted open rotor engine).

[0039] Still reference Figure 1 and Figure 2, the turbofan engine 100 also includes a controller 150, and although not depicted, one or more sensors. The controller 150 may be a full authority digital thrust control system, also referred to as a FADEC. The controller 150 of the turbofan engine 100 may be configured to control the operation of, for example, the actuating member 132, a fuel delivery system 151 to the combustion section 114 (the controller 150 may be operable to adjust the amount of fuel provided to the combustion section 114 by the fuel delivery system 151), and the like. In addition, the controller 150 may be operably connected to one or more sensors to receive data from the sensors and determine various operating parameters of the turbofan engine 100. For example, the controller 150 may determine one or more of the exhaust temperature, the rotational speed of the core (i.e., the rotational speed of the HP system), the compressor discharge temperature, and the like. In addition, return to reference Figure 1 , the controller 150 of the turbofan engine 100 is operably connected to the controller 72 of the hybrid electric propulsion system 50. In addition, as will be understood, the controller 72 may also be operably connected to one or more of the first gas turbine engine 100A, the second gas turbine engine 100B, the energy storage unit 57, etc. via a suitable wired or wireless communication system (depicted in dashed lines).

[0040] Special return reference Figure 1 and Figure 2 The electrical system of the hybrid electric propulsion system 50 includes one or more electric machines (e.g., electric machine 56A, schematically depicted) mechanically coupled to the first gas turbine engine 100A and one or more electric machines (e.g., electric machine 56B, schematically depicted) mechanically coupled to the second gas turbine engine 100B. Although schematically depicted outside of the respective gas turbine engines 100A, 100B, in certain embodiments, the electric machines 56A, 56B may be positioned within a respective one of the gas turbine engines 100A, 100B (see, e.g., Figure 3 ). In addition, although a single electric machine is depicted with each gas turbine engine 100A, 100B, in certain embodiments, multiple electric machines 56A, 56B may be provided for each gas turbine engine (e.g., electric machines 56A-1, 56A-2 for gas turbine engine 100A and electric machines 56B-1, 56B-2 for gas turbine engine 100B).

[0041] In addition, as mentioned above Figure 3 Briefly mentioned, Figure 1 and Figure 2In an embodiment of the hybrid electric propulsion assembly 50, the hybrid electric propulsion assembly 50 also includes a controller 72. As will be appreciated, the energy storage unit 57 may be configured to receive electrical power from one or both of the first motor 56A and the second motor 56B under certain operating conditions, and may be further configured to provide the stored electrical power to one or both of the first motor 56A and the second motor 56B under certain operating conditions. In addition, the controller 72 may be operably connected to the turbofan engines 100A, 100B, the motors 56A, 56B, and the energy storage unit 57 to, for example, control the operation of the hybrid electric propulsion system 50 during various operating conditions, and selectively electrically connect components of the hybrid electric propulsion system 50.

[0042] Additionally, controller 72 may communicate with one or more aircraft controllers to receive data indicative of an aircraft demand for electrical power and may responsively provide electrical power from one or more of motors 56A, 56B and energy storage unit 57 to aircraft loads 74 .

[0043] However, it should be understood that in other exemplary embodiments of the present disclosure, any other suitable aircraft 10 may be provided having a hybrid electric propulsion system 50 configured in any other suitable manner. For example, in other embodiments, the turbofan engines 100A, 100B may each be configured as any other suitable combustion engine (e.g., a turboprop engine, a non-ducted turbofan engine, a turboshaft engine, a turbojet engine, etc.) and may be installed in any other suitable location.

[0044] Furthermore, in other exemplary embodiments, the exemplary hybrid electric propulsion system 50 may have other configurations. For example, referring now briefly to Figure 4 , a schematic diagram of a hybrid electric propulsion system 50 according to yet another exemplary embodiment of the present disclosure is provided. Figure 4 The exemplary hybrid electric propulsion system 50 depicted in FIG. 5 may be similar to the one described above with reference to FIG. Figures 1 to 3 One or more exemplary hybrid-electric propulsion systems 50 are described.

[0045] In various embodiments, the hybrid electric propulsion system 50 may include at least two propellers. For example, the hybrid electric propulsion system 50 may include a first propeller 52 and a second propeller 54. The first propeller 52 generally includes a first engine 100A having a first turbine 102A and a first fan 104A, and a second engine 100B having a second turbine 102B and a second fan 104B. Each of the first and second turbines 102A, 102B generally includes a low-pressure system and a high-pressure system, the low-pressure system having a low-pressure compressor 110A, 110B drivenly coupled to a low-pressure turbine 118A, 118B through a low-pressure shaft 124A, 124B, and the high-pressure system having a high-pressure compressor 112A, 112B drivenly coupled to a high-pressure turbine 116A, 116B through a high-pressure shaft 122A, 122B.

[0046] Additionally, the first fan 104A is drivingly coupled to the low pressure system of the first turbine 102A (e.g., via the low pressure shaft 124A), and the second fan 104B is drivingly coupled to the low pressure system of the second turbine 102B (e.g., via the high pressure shaft 124B). In certain exemplary embodiments, the first fan 104A and the first turbine 102A may be configured as a first turbofan engine, and similarly, the second fan 104B and the second turbine 102B may be configured as a second turbofan engine (see, e.g., Figure 3 ). However, alternatively, these components may alternatively be configured as part of a turboprop engine or any other suitable turbine-driven propulsion device.

[0047] also, Figure 4 The hybrid electric propulsion system 50 also includes an electrical system. More specifically, the hybrid electric propulsion system 50 includes one or more motors operable with the first engine 100A, the second engine 100B, or both, and an electrical energy storage unit 57 electrically connected to one or more of the motors. In particular, for the described embodiment, the hybrid electric propulsion system 50 includes a first motor 56A-1 and a second motor 56A-2 operable with the first engine 100A, and a first motor 56B-1 and a second motor 56B-2 operable with the second engine 100B.

[0048] More specifically, for Figure 4 In the embodiment depicted in FIG, the first electric machines 56A-1, 56B-1 are each coupled to a high pressure system of a corresponding turbine 102A, 102B (such as coupled to a high pressure shaft 124A, 124B), and the second electric machines 56A-2, 56B-2 are each coupled to a low pressure system of a corresponding turbine 102A, 102B (such as coupled to a low pressure shaft 122A, 122B).

[0049] In many embodiments, each of the turbines 100A, 100B may each include a fuel delivery system 151A, 151B. For example, the first turbine 100A may include a first fuel delivery system 151A fluidly connected to the combustion section 114A of the first turbine 100A. Similarly, the second turbine 100B may include a second fuel delivery system 151B fluidly connected to the combustion section 114B of the second turbine 100B. The fuel delivery systems 151A, 151B may each include one or more fuel supply parts (such as fuel tanks), one or more fuel pumps, one or more valves and a fuel controller. The fuel delivery systems 151A, 151B are operable to adjust the amount of fuel supplied to the respective combustion systems 114A, 114B (e.g., by actuating one or more valves). The fuel controller for each fuel delivery system 151A, 151B may be integrated into the FADEC, or may be an independent controller. The fuel controller can be operably connected to one or more pumps and / or one or more valves of the fuel delivery system so that the fuel controller can adjust the amount of fuel supplied to the combustion section (e.g., by setting a fuel command, thereby actuating one or more valves and / or modifying the power level of one or more pumps).

[0050] Also like Figure 4 As depicted in , the exemplary hybrid electric propulsion system 50 also includes an electric bus 58. The first motor 56A-1, 56A-2, the second motor 56B-1, 56B-2, and the electrical energy storage unit 57 can each be electrically connected to each other via one or more wires 60 of the electric bus 58. For example, the electric bus 58 can include various switches or other power electronic devices that are movable to selectively electrically connect various components of the hybrid electric propulsion system 50 and optionally convert or regulate such electrical power transmitted therethrough. The various switches and other power electronic devices can be operably connected to the controller so that the controller can control the power flowing to and / or from the first motor 56A-1, 56A-2, the second motor 56B-1, 56B-2, and the electrical energy storage unit 57.

[0051] In addition, Figure 4 As depicted in the example of FIG, the power bus 58 is electrically connected to one or more aircraft systems 74 for providing electrical power from one or more of the first motors 56A-1, 56A-2, the second motors 56B-1, 56B-2, and the electrical energy storage unit 57 to the one or more aircraft systems 74. The one or more aircraft systems 74 may include, for example, environmental control, aircraft control, hydraulic systems, pumps, de-icing systems, navigation, lighting, heating, etc.

[0052] In many embodiments, the propulsion system 50 may include one or more sensors operably connected to any (or all) of the FADEC A 156, FADEC B 158, and the supervisory controller 300, so that the one or more sensors can provide sensed data to the controller. The one or more sensors can each be coupled to the propellers 52, 54, and can each be configured to sense data indicating the angle of the fan blades relative to a reference line. For example, the one or more sensors can include a first sensor 230A coupled to the first propeller 52 and a second sensor 230B coupled to the second propeller 54. The first sensor 230A is operable to sense data indicating a first angle of the blades of the first fan 104A relative to a reference line (such as a vertical reference line). Similarly, the second sensor 230B is operable to sense data indicating a second angle of the blades of the second fan 104B relative to a reference line (such as a vertical reference line). The supervisory controller 300 can receive the data indicating the first angle and the data indicating the second angle, and the supervisory controller 300 can determine the paired phase difference between the first propeller and the second propeller (i.e., or the phase angle between the first propeller 52 and the second propeller).

[0053] in addition, Figure 4 The system depicted in FIG. 1 includes a supervisory controller 300 (which may be similar to the controller 72 described above), a first gas turbine engine controller 156 (which may be, for example, a FADEC controller), and a second gas turbine engine controller 158 (which may also be, for example, a FADEC controller). The supervisory controller 300 may receive data indicating one or more operability parameters of the first gas turbine engine 100A, the second gas turbine engine 100B, or both. For example, the exemplary supervisory controller 300 may receive data indicating: one or more fuel flows, one or more operating temperatures (e.g., exhaust gas temperature, compressor outlet temperature, turbine inlet temperature, etc.), one or more speeds of the gas turbine engine (e.g., speed of the low pressure system, speed of the high pressure system, speed of the fan / propeller, etc.), a phase angle difference between the fans / propellers of each propeller, one or more shaft torques, one or more pressure measurements, one or more thrust outputs (which may be, for example, a calculation from a combination of fan / propeller speed and fan / propeller pitch angle), a serial number or other unique component identifier identifying a component (such as an identifier of one or more engines), an estimate or measurement of component consumption or remaining life or performance, any combination of these or calculations derived therefrom, etc.

[0054] In particular, the supervisory controller 300 may receive data indicating the angle of the fan blades of each of the fans 104A, 104B at a certain moment relative to a vertical reference line, for example, from the sensors 230A, 230B. The supervisory controller 300 may utilize the data indicating the angles to determine the phase angle between the first fan 104A and the second fan 104B. As used herein, in an aircraft or propulsion system having multiple thrusters, "phase angle" refers to the position of a fan blade on a first fan of a first thruster of the plurality of thrusters relative to the position of a fan blade on a different fan of a different thruster of the plurality of thrusters.

[0055] The supervisory controller 300 includes controller logic 350. The controller logic 350 may be a set of computer executable instructions stored in a memory that, when executed by one or more processors of the supervisory controller 300, cause the one or more processors to implement a synchronized phasing control scheme. In implementing the synchronized phasing control scheme, the one or more processors may: determine a phase angle between the first fan 104A and the second fan 104B; generate a reference phase angle (e.g., a desired phase angle between the first fan 104A and the second fan 104B); determine a target phase shift for each fan 104A, 104B; and cause the speed of each propeller 52, 54 to be adjusted based on the target phase shift until the phase angle equals the reference phase angle. For example, the supervisory controller 300 may instruct the propulsion system 50 to adjust the speed of each propeller 52, 54 of at least two propellers based on the target phase shift until the paired phase difference equals the reference phase angle. In particular, adjusting the speed of each thruster 52, 54 may include adjusting the amount of fuel provided to the combustion section 114A, 114B of each thruster 52, 54 from the fuel delivery system 151A, 151B based on the target phase shift (e.g., increasing or decreasing the amount of fuel provided). Additionally or alternatively, adjusting the speed of each thruster may include adjusting the amount of power transferred between the motor 56A-1, 56A-2, 56B-1, 56B-2 and the shaft 122 and / or 124. For example, adjusting the amount of power transferred between the motors 56A-1, 56A-2, 56B-1, 56B-2 and the shafts 122 and / or 124 may include any of the following: (1) transferring power from the first engine 100A to the second engine 100B, or vice versa; (2) transferring power from the electrical energy storage unit 57, the first engine 100A, or both to the second engine 100B, or from the electrical energy storage unit 57, the second engine 100B, or both to the first engine 100A; (3) transferring power from the low-pressure system of one of the first or second engines 100A, 100B to the high-pressure system of the same engine, or vice versa; and / or (4) extracting different amounts of power from the first and second engines 100A, 100B. In this manner, the system may adjust the phase angle between fans 104A, 104B to a reference phase angle (such as a reference phase angle of zero in some embodiments or a non-zero reference phase angle in other embodiments) and / or may synchronize the speeds of fans 104A, 104B.

[0056] Figure 5 and Figure 6 Each shows a schematic diagram of an aircraft 50 having a propulsion system 50 with at least two thrusters according to an embodiment of the present disclosure. In particular, Figure 5A propulsion system 50 is shown having two propellers (e.g., a first propeller 52 mounted on the first wing 20 of the aircraft 10, and a second propeller 54 mounted on the second wing 22 of the aircraft 10). Each of the propellers 52, 54 may be similar to Figure 3 1 and described above. Figure 6 A propulsion system 50 is shown having four propellers (e.g., a first propeller 52 and a second propeller 54 mounted on the first wing 20 of the aircraft 10, and a third propeller 53 and a fourth propeller 55 mounted on the second wing 22 of the aircraft 10). Each of the propellers 52, 53, 54, 55 may be similar to Figure 3 1 and described above.

[0057] Each of the propellers 52, 53, 54, 55 may include a fan (e.g., a first fan 104A, a second fan 104B, a third fan 104C, and a fourth fan 104D) having a plurality of fan blades. For example, the first fan 104A may have a first plurality of fan blades 128A extending outward (e.g., radially outward) from the first disk 130A. The second fan 104B may have a second plurality of fan blades 128B extending outward (e.g., radially outward) from the second disk 130B. The third fan 104C may have a third plurality of fan blades 128C extending outward (e.g., radially outward) from the third disk 130C. The fourth fan 104D may have a fourth plurality of fan blades 128D extending outward (e.g., radially outward) from the fourth disk 130D. Returning to Reference Briefly Figure 3 Each fan blade 128 is rotatable relative to disk 130 about a respective pitch axis P by virtue of fan blades 128 being operably coupled to suitable actuation members 132 that are configured to collectively vary the pitch of fan blades 128 .

[0058] Each of the thrusters 52, 53, 54, 55 may define a top dead center (TDC) reference line. The TDC reference line may extend vertically (eg, along a vertical direction V) through a center point of each thruster 52, 53, 54, 55 (eg, the TDC reference line may be aligned with the center point of the thruster 52, 53, 54, 55). Figure 3). In particular, the first thruster 52 may include a first TDC reference line 202, the second thruster 54 may include a second TDC reference line 204, the third thruster 53 may include a third TDC reference line 203, and the fourth thruster 55 may include a fourth TDC reference line 205. Notably, in order to calculate the phase angle, the reference lines (such as TDC reference lines) do not necessarily need to be vertical, as long as the reference line of each thruster is similarly oriented (e.g., parallel) and extends through the center of the corresponding thruster (or intersects the center of the corresponding thruster).

[0059] The propulsion system 50 may include a supervisory controller 300, which may include one or more processors and one or more memory devices. Additionally, the supervisory controller 300 may include controller logic 350, which may be a set of computer executable instructions stored in a memory that, when executed by one or more processors of the supervisory controller 300, causes the one or more processors to implement a synchronized phasing control scheme.

[0060] In many embodiments, such as Figure 6 As shown, the supervisory controller may also include a digital thruster 352. The digital thruster 352 may virtually represent an additional thruster. The digital thruster 352 may include parameters and dimensions of one or more physical thrusters 52, 53, 54, 55 that provide measured values ​​and keep the values ​​of those parameters and dimensions up to date by receiving and updating values ​​via outputs from sensors embedded in the physical thrusters 52, 53, 54, 55. The digital thruster 352 may have corresponding virtual components corresponding to substantially all physical and operational components of the physical thrusters 52, 53, 54, 55. In this way, as an alternative to one or more of the physical thrusters 52, 53, 54, 55, or in addition to one or more of the physical thrusters 52, 53, 54, 55, the supervisory controller 300 may utilize the digital thruster 352 to determine a paired phase difference, generate a reference phase angle, determine a target phase shift, and / or adjust each engine speed until the paired phase difference equals the reference phase angle.

[0061] The supervisory controller 300 may be in operative communication with each of the propellers 52, 53, 54, 55 such that the supervisory controller 300 may receive data indicative of operating parameters associated with the propellers 52, 53, 54, 55. For example, the exemplary supervisory controller 300 may receive data indicative of one or more fuel flows, one or more operating temperatures (e.g., exhaust gas temperature, compressor outlet temperature, turbine inlet temperature, etc.), one or more speeds of the gas turbine engine (e.g., rotational speed of the low pressure system, rotational speed of the high pressure system, rotational speed of the fan / propeller, etc.), one or more shaft torques, one or more pressure measurements, one or more thrust outputs (which may be, for example, a calculation based on a combination of fan / propeller speed and fan / propeller pitch angle), vibration measurements or estimates of each engine, or vibrations associated with components of each engine, etc.

[0062] like Figure 5 and Figure 6 As shown in FIG. 1 , at a particular moment (i.e., a certain moment), the supervisory controller 300 may determine or receive (e.g., by measuring, sensing, or estimating) a set of angles 302 between the fan blades 128 of each fan and a reference line. The angles 302 may then be compared to one another to determine a pairwise phase difference between a corresponding pair of angles 302. The angles 302 may be defined in a vertical longitudinal plane (e.g., Figure 5 and Figure 6 ). For example, the first propeller 52 defines a first angle θ1 between the first reference line 202 and the fan blade 128A of the first plurality of fan blades 128A that is closest to the first TDC reference line 202 at a certain moment. The second propeller 54 defines a second angle θ2 between the second reference line 204 and the fan blade 128B of the second plurality of fan blades 128B that is closest to the second TDC reference line 204 at this moment. The third propeller 53 defines a third angle θ3 between the third TDC reference line 204 and the fan blade 128C of the third plurality of fan blades 128C that is closest to the third TDC reference line 204 at this moment. The fourth propeller 55 defines a fourth angle θ4 between the fourth TDC reference line 205 and the fan blade 128D of the fourth plurality of fan blades 128D that is closest to the fourth TDC reference line 205 at this moment. For example, angle 302 may be between about 0° and about 360°, or such as between about 0° and about 180°, or such as between about 0° and about 90°, or such as between about 0° and about 30°, or such as between about 0° and about 5°.

[0063] In some embodiments, supervisory controller 300 may obtain information from one or more sensors (e.g., Figure 4The sensor 230 described above receives the angle 302. In other embodiments, the angle 302 may be estimated (e.g., calculated), for example, based on other operating parameters of the aircraft 10 and / or the thrusters 52, 53, 54, 55, such as the speed of the LP shaft, the speed of the HP shaft, and / or vibrations of the thrusters. For example, the angle may be calculated by comparing various speeds of each of the thrusters 52, 53, 54, 55 relative to each other or relative to a digital thruster.

[0064] like Figure 5 and Figure 6 As shown in , the control logic 350 may include determining a pairwise phase difference (PPD) between one of the at least two thrusters and another of the at least two thrusters at (306). The pairwise phase difference (i.e., the phase angle of the particular two thrusters) may be the difference between the angle θ of one of the at least two thrusters and the angle θ of the other of the at least two thrusters at a certain moment. For example, for Figure 5 In the embodiment shown in , PPD may be the difference between the first angle θ1 and the second angle θ2 at that moment.

[0065] for Figure 6 , the controller logic 350 may determine multiple PPDs for a particular thruster relative to other thrusters. For example, in an embodiment where the first thruster 52 is the reference thruster, the first PPD between the first thruster 52 and the second thruster 54 may be 12 The second PPD between the first propeller 52 and the third propeller 53 can be determined by obtaining the difference between the first angle θ1 and the second angle θ2 at a certain moment; 13 The third PPD between the first propeller 52 and the fourth propeller 55 can be determined by obtaining the difference between the first angle θ1 and the third angle θ3 at this moment; and 14 It can be determined by obtaining the difference between the first angle θ1 and the fourth angle θ4 at that moment. In some cases, PPD 12 、PPD 13 、PPD 14 Each of can be the same (e.g., equal to each other). In other cases, PPD 12 、PPD 13 、PPD 14 Each of may be different (eg, not equal to each other).

[0066] Additionally, in many embodiments, the controller logic 350 may include generating a reference phase angle (RPA) at (308) that is different from the current paired phase difference. The reference phase angle may be a desired phase angle between the thrusters (i.e., a desired paired phase difference). The RPA may be generated based on one or more gas turbine operating parameters (such as vibration, speed, or other parameters). In many embodiments, the RPA may be equal to zero such that after a phase shift occurs, the phase angle or paired phase difference is equal to zero. Alternatively, the RPA may be non-zero such that after a phase shift occurs, the phase angle or paired phase difference is equal to a non-zero value.

[0067] exist Figure 5 In the illustrated embodiment, the supervisory controller 300 may generate only one reference phase angle RPA between the first propeller 52 and the second propeller 54. 12 .for Figure 6 In the embodiment shown in FIG. 1 , the supervisory controller 300 may generate multiple RPAs that are all relative to the same reference thruster. For example, with the first thruster as the reference thruster, the supervisory controller 300 may generate: a first RPA between the first thruster 52 and the second thruster 54 12 ; A second RPA between the first propeller 52 and the third propeller 53 13 ; and a third RPA between the first propeller 52 and the fourth propeller 55 14 .

[0068] In an exemplary embodiment, the controller logic 350 may include determining a target phase shift (TPS) for each of the at least two thrusters based at least in part on the reference phase angle and the pairwise phase difference at (310). The target phase shift may be an amount (e.g., in degrees) by which the angle 302 of each thruster may be adjusted (e.g., by adding / removing power with an electric motor, adjusting the amount of fuel provided to the combustion section, and / or adjusting the pitch of the fan blades) to achieve the RPA.

[0069] In an exemplary embodiment, the TPS can be determined at (312) by minimizing a cost function. A cost function is a mathematical function that represents a goal or objective that a system is trying to achieve. In this case, the goal of the cost function is to minimize the phase shift (e.g., the minimum amount that each angle θ needs to be adjusted to collectively achieve RPA). In this way, each of the thrusters can be shifted in phase independently of each other to achieve RPA in the most efficient manner.

[0070] In particular, for Figure 5 In the embodiment shown in (eg, an aircraft 10 having two thrusters), the objective of the cost function may be to minimize the following equation (cost function):

[0071]

[0072] In equation (1), TPS1 is the target phase shift of the first thruster, and TPS2 is the target phase shift of the second thruster. The above equation (1) (ie, the cost function) may be subject to the following equation (eg, the following equation must hold true when the cost equation is minimized):

[0073] TPS1+TPS2=PPD 12 - RPA 12 (2).

[0074] In equation (2), PPD 12 is the current paired phase difference between the first propeller 52 and the second propeller 54, which can be determined by obtaining the difference between the first angle θ1 and the second angle θ2 at a certain moment (eg, the current moment), and RPA 12 is a reference phase angle (e.g., a desired or target phase angle) between the first thruster 52 and the second thruster 54. The supervisory controller may iteratively minimize the cost equation (e.g., continuously testing TPS1 and TPS2 values ​​to converge to a minimum value of the cost function while maintaining equation 2 as true). That is, the cost function may be iteratively minimized by continuously testing TPS1 and TPS2 to converge to TPS1 and TPS2 for each of the at least two thrusters while maintaining equation (2) as true.

[0075] for Figure 6 , the cost function may be different (e.g., for aircraft with more than two thrusters and / or digital thrusters). Figure 6 In the embodiment shown in , the objective of the cost function may be to minimize the following equation:

[0076]

[0077] In equation (3), TPS1 is the target phase shift for the first thruster 52; TPS2 is the target phase shift for the second thruster 54; TPS3 is the target phase shift for the third thruster 53; and TPS4 is the target phase shift for the fourth thruster 55. Additionally, k1, k2, k3, k4 may each be an energy cost (or any other operating cost) associated with the phase shift for each thruster, which may be a constant value and may be predetermined and stored in memory, or may be calculated based on operating conditions.

[0078] It is worth noting that the cost functions discussed above (e.g., equations (1) and (3)) are used as examples of cost functions that can be minimized to determine the target phase shift for the systems described herein. It should be understood that the systems described herein can utilize other cost functions to determine / generate the target phase shift for each engine based at least in part on the reference phase angle and the pairwise phase difference, and unless specifically recited in the claims, the subject matter should not be limited to any particular cost function.

[0079] The above equation (3) (ie, the cost function) may be subject to the following equation (eg, the following equation must hold true when the cost equation is minimized):

[0080] TPS1+TPS D =0 (4)

[0081] TPS1+TPS2=PPD 12 - RPA 12 (5)

[0082] TPS1+TPS3=PPD 13 - RPA 13 (6)

[0083] TPS1+TPS4=PPD 14 - RPA 14 (7).

[0084] In equations (4)-(7), PPD 12 is the current paired phase difference between the first propeller 52 and the second propeller 54, which can be determined by obtaining the difference between the first angle θ1 and the second angle θ2 at a certain moment; PPD 13 is the current paired phase difference between the first propeller 52 and the third propeller 53, which can be determined by obtaining the difference between the first angle θ1 and the third angle θ3 at that moment; and PPD 14 is the current paired phase difference between the first propeller 52 and the fourth propeller 55, which can be determined by obtaining the difference between the first angle θ1 and the fourth angle θ4 at that moment. TPS D is the target phase shift of the digital pusher 152. In addition, the first RPA between the first pusher 52 and the second pusher 54 12 ; A second RPA between the first propeller 52 and the third propeller 53 13 ; and a third RPA between the first propeller 52 and the fourth propeller 55 14 .

[0085] As shown in equation (4), the paired phase difference between the digital thruster 152 and at least one other of the at least two thrusters can be zero. For example, doing so can simplify the calculation of the target phase shift. Alternatively, the paired phase difference between the digital thruster 152 and at least one other of the at least two thrusters can be non-zero. The supervisory controller 300 can iteratively minimize the cost equation (e.g., continuously testing TPS1, TPS2, TPS3, and TPS4 values ​​to converge to a minimum value of the cost function while keeping equations 4 to 7 true).

[0086] Notably, each of the two or more thrusters (e.g., a first thruster, a second thruster, a third thruster, and a fourth thruster) can be compared to the digital thruster 152. For example, the pairwise phase differences of each thruster can be compared to the pairwise phase differences of the digital thruster 152, which can be advantageously used to determine a target phase shift for each thruster.

[0087] In an exemplary embodiment, the controller logic 350 may further include adjusting the angle 302 of each of the at least two thrusters based on the determined TPS1, TPS2, TPS3, and TPS4 that minimizes the cost function to achieve the desired RPA. Adjusting the angle 302 may include independently adjusting each of the angles θ (e.g., shifting the phase by a certain number of degrees) based on the determined TPS. In an exemplary embodiment, this may be performed at (314) by adjusting the speed of each of the at least two thrusters based on the target phase shift until the paired phase difference equals the reference phase angle. For example, if the paired phase difference is equal to approximately 30° (i.e., the difference between θ1 and θ2 is equal to approximately 30°), and the reference phase angle is generated to be equal to approximately 15°, then TPS1 and TPS2 may be determined (e.g., by minimizing the cost function), and the speed of each thruster may be adjusted until the paired phase difference is reduced from 30° to approximately 15°. By minimizing the cost function, the system may determine that TPS1 is positive 10° and TPS2 is negative 5°. That is, when the current paired phase difference is about 30°, in order to achieve a desired reference phase angle of about 15°, the first thruster needs a positive phase shift of about 10°, and the second thruster needs a negative phase shift of about 5°. The positive phase shift can be performed by accelerating (i.e., increasing the speed) the first thruster, while the negative phase shift can be performed by slowing down (i.e., reducing the speed) the first thruster.

[0088] For example, the supervisory controller 300 may generate one or more control signals 301 that may be communicated to one or more controllable devices 304 of each of the thrusters 52, 53, 54, 55. For example, the controllable devices 304 may include motors 316, such as those described above with reference to Figure 3The controllable device 304 may also include a fuel delivery system 318, such as the one described above with reference to Figure 3 and Figure 4 The controllable device 304 may also include a fan blade pitch 320, for example, by actuating an actuating member 132 connected to the fan blade 128 (see Figure 3 ).

[0089] The speed (rotational speed of the shaft) and angle 302 (and therefore the phase angle) can be adjusted by the motor 316 by adjusting the rotational speed of the shaft, which can be achieved by transferring power (e.g., adding or removing) between the motor 316 and the shaft. In particular, the speed and angle 302 (and therefore the phase angle) can be adjusted by transferring power (e.g., adding or removing) between the motor 316 and the LP shaft. Additionally, the speed (e.g., rotational speed) and angle 302 (and therefore the phase angle) can be adjusted by adjusting the amount of fuel provided to the combustion section of the thruster. Furthermore, the speed and angle 302 (and therefore the phase angle) can be adjusted by adjusting the fan blade pitch.

[0090] Reference now Figure 7 , a flow chart of one embodiment of a method 700 of operating a propulsion system is shown according to an embodiment of the present subject matter. Figure 1-6 The method 700 is described with reference to the propulsion system 50, thrusters 52, 53, 54, 55, aircraft 10, gas turbine engine 100, supervisory controller 300, and control logic 350. However, one of ordinary skill in the art will appreciate that the disclosed method 700 may generally be used with any suitable turbine and / or may be used in conjunction with a system having any other suitable system configuration. In addition, although for purposes of illustration and discussion, Figure 7 The steps are depicted to be performed in a particular order, but unless otherwise specified in the claims, the methods discussed herein are not limited to any particular order or arrangement. Using the disclosure provided herein, those skilled in the art will understand that the various steps of the methods disclosed herein may be omitted, rearranged, combined and / or adjusted in various ways without departing from the scope of the present disclosure.

[0091] As discussed above, the propulsion system of method 700 may include determining a pairwise phase difference (PPD) between one of the at least two propellers and another of the at least two propellers at (702). The pairwise phase difference (i.e., the phase angles of the particular two propellers) may be the difference between an angle θ of one of the at least two propellers and an angle θ of the other of the at least two propellers at a certain moment in time. For example, at a certain moment in time (i.e., a certain moment in time), the supervisory controller may determine or receive (e.g., by measuring, sensing, or estimating) an angle between a reference line and a propeller blade of each fan closest to the reference line, and these angles may then be compared to each other (e.g., by taking the absolute value of the difference) to determine the pairwise phase difference.

[0092] In a propulsion system or aircraft having more than two thrusters, method 700 may include generating multiple pairs of thrusters (e.g., a first pair between thruster one and thruster two, a second pair between thruster one and thruster three, a third pair between thruster one and thruster four, etc.) that are all relative to the same reference thruster. Subsequently, method 700 may include generating a pairwise phase difference for each pair of thrusters.

[0093] In an exemplary embodiment, method 700 may also include generating a reference phase angle different from the paired phase difference at (704). For example, the reference phase angle may be a desired or target paired phase difference between a given pair of thrusters, the desired or target paired phase difference being different from the current paired phase difference between the same pair of thrusters. The reference phase angle may be generated based on the operating conditions of the thrusters. In this manner, method 700 may include generating a reference phase angle for each pair of thrusters. In some embodiments, method 700 may include generating reference phase angles that are different from each other for one or more pairs of thrusters in a plurality of pairs of thrusters (e.g., a first pair of thrusters having a first reference phase angle that is different from a second reference phase angle of a second pair of thrusters, etc.). Alternatively or additionally, method 700 may include generating the same (e.g., equal) reference phase angles for one or more pairs of thrusters in a plurality of pairs of thrusters.

[0094] In particular, if Figure 7 As shown in , the method may include generating a reference phase angle of zero at (706). More specifically, method 700 may include generating a reference phase angle of zero for one or more pairs of thrusters in the plurality of pairs of thrusters, such that after the speed is adjusted, the one or more pairs of thrusters will ultimately be driven to a paired phase difference of zero. Alternatively or additionally, the method may include generating a reference phase angle of non-zero at (708). More specifically, method 700 may include generating a reference phase angle of non-zero for one or more pairs of thrusters in the plurality of pairs of thrusters, such that after the speed is adjusted, the one or more pairs of thrusters will ultimately be driven to a paired phase difference of non-zero.

[0095] In an exemplary embodiment, method 700 may also include determining a target phase shift for each of the at least two thrusters based at least in part on the reference phase angle and the paired phase difference at (710). The target phase shift may be an amount (e.g., in degrees) by which the angle θ of each thruster may be adjusted (e.g., by adding / removing power with an electric motor, adjusting the amount of fuel provided to the combustion section, and / or adjusting the pitch of the fan blades) to achieve the generated reference phase angle. In many embodiments, method 700 may include minimizing a cost function at (712) to determine the target phase shift for each of the at least two thrusters. Minimizing the cost function may be performed iteratively, for example, by continuously testing values ​​of the target phase shift to ultimately converge on a minimum value of the cost function.

[0096] In many embodiments, the method may include adjusting the angle θ of each of the at least two thrusters according to the determined target phase shift that minimizes the cost function to achieve the desired RPA. Adjusting the angle θ may include independently adjusting each of the angles θ according to the determined target phase shift (e.g., by independently offsetting the angle θ by a certain number of degrees). In an exemplary embodiment, the method 700 may include adjusting the speed of each of the at least two thrusters based on the target phase shift at (714) until the paired phase difference equals the reference phase angle. In particular, the controller may instruct the gas turbine system to adjust the speed of each of the at least two thrusters based on the target phase shift until the paired phase difference equals the reference phase angle. The speed (speed of the HP and / or LP shaft) and angle (and therefore the phase angle) of each thruster may be adjusted by a motor coupled to the LP shaft and / or HP shaft of each respective thruster. For example, the motor may transfer power between the motor and the shaft (e.g., add power or remove power). In particular, the speed and angle 302 (and therefore the phase angle) may be adjusted by transferring power between the motor 316 and the shaft (e.g., add or remove). Additionally or alternatively, the speed (eg, shaft speed) and angle 302 (and thus phase angle) may be adjusted by adjusting the amount of fuel provided to the combustion section using a fuel delivery system. In various implementations, the shaft speed may be adjusted over a period of time to achieve a desired RPA.

[0097] Figure 8 A block diagram of an example computing system 600 is provided. The computing system 600 may be used to implement aspects disclosed herein. The computing system 600 may include one or more computing devices 602. For example, the controller 72, the first gas turbine engine controller 156, the second gas turbine engine controller 158, the supervisory controller 300, and / or the fuel controller disclosed herein may be constructed and operated in the same or similar manner as one of the computing devices 602.

[0098] like Figure 8 As shown in , one or more computing devices 602 may each include one or more processors 604 and one or more memory devices 606. One or more processors 604 may include any suitable processing device, such as a microprocessor, a microcontroller, an integrated circuit, a logic device, or other suitable processing device. One or more memory devices 606 may include one or more computer-readable media, including but not limited to one or more non-transitory computer-readable media, RAM, ROM, hard disk drives, flash drives, and other memory devices, such as one or more buffer devices.

[0099] The one or more memory devices 606 may store information accessible by the one or more processors 604, including computer-readable or computer-executable instructions 608 that may be executed by the one or more processors 604. The instructions 608 may be any set of instructions or control logic that causes the one or more processors 604 to operate when executed by the one or more processors 604. The instructions 608 may be software written in any suitable programming language, or may be implemented in hardware. In some embodiments, the instructions 608 may be executed by the one or more processors 604 to cause the one or more processors 604 to operate.

[0100] The memory device 606 may further store data 610 that may be accessed by the processor 604. For example, the data 610 may include sensor data, such as engine parameters as described herein, model data, logic data, etc. According to an example embodiment of the present disclosure, the data 610 may include one or more tables, functions, algorithms, models, equations, etc.

[0101] The one or more computing devices 602 may also include a communication interface 612 for communicating with other components of the aircraft, for example. The communication interface 612 may include any suitable components for interfacing with one or more networks, including, for example, a transmitter, a receiver, a port, a controller, an antenna, or other suitable components.

[0102] The technology discussed herein refers to computer-based systems, actions taken by computer-based systems, information sent to computer-based systems, and information sent from computer-based systems. It should be understood that the inherent flexibility of computer-based systems allows for various possible configurations, combinations, and divisions of tasks and functions between and within components. For example, the processing discussed herein can be implemented using a single computing device or multiple computing devices working in combination. Databases, memories, instructions, and applications can be implemented on a single system, or can be distributed on multiple systems.

[0103] 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.

[0104] The present disclosure provides various control methods for generating target phase shift values ​​optimized according to a cost function, thereby allowing each of the thrusters to shift phase independently of each other to achieve a reference phase angle in the most efficient manner. This can be advantageous over, for example, modifying the phase angle by shifting one thruster by an angle while another thruster does not shift by an angle, because this consumes less time and energy, which has a positive impact on the performance of the propulsion system.

[0105] Further aspects are provided by the subject matter of the following clauses:

[0106] A propulsion system comprises: at least two propellers, each of the at least two propellers comprising a fan having a plurality of fan blades; and a controller comprising a memory and one or more processors, the memory storing instructions that, when executed by the one or more processors, cause the system to perform the following operations: determine a paired phase difference between one of the at least two propellers and another of the at least two propellers; generate a reference phase angle different from the paired phase difference; determine a target phase shift for each of the at least two propellers based at least in part on the reference phase angle and the paired phase difference; and adjust a speed of each of the at least two propellers based on the target phase shift until the paired phase difference equals the reference phase angle.

[0107] A propulsion system as described in any preceding clause, wherein the target phase shift for each thruster is determined to minimize a cost function.

[0108] A propulsion system according to any preceding clause, wherein the at least two thrusters include a first thruster, a second thruster, and a third thruster, wherein the paired phase difference is a first paired phase difference between the first thruster and the second thruster, and wherein the one or more processors are further constructed to: determine a second paired phase difference between the first thruster and the third thruster, and wherein the first paired phase difference is different from the second paired phase difference.

[0109] A propulsion system as described in any preceding clause, wherein at least one of the at least two thrusters is a digital thruster.

[0110] A propulsion system as described in any preceding clause, wherein a pairwise phase difference between the digital thruster and at least one other thruster of the at least two thrusters is zero.

[0111] A propulsion system according to any preceding clause, wherein the at least two propellers include a first propeller and a second propeller, the first propeller including a first fan having a first plurality of fan blades, the second propeller having a second fan having a second plurality of fan blades, wherein the first propeller defines a first angle between a first top dead center (TDC) reference line and a fan blade of the first plurality of fan blades that is closest to the first TDC reference line at a certain moment, wherein the second propeller defines a second angle between a second TDC reference line and a fan blade of the second plurality of fan blades that is closest to the second TDC reference line at the moment, and wherein the paired phase difference is the difference between the first angle and the second angle at the moment.

[0112] A propulsion system according to any of the preceding clauses, wherein each of the at least two propellers further comprises a shaft and a motor operably connected to the shaft, and wherein adjusting the speed of each of the at least two propellers comprises adjusting the rotational speed of the shaft by transferring power between the motor and the shaft.

[0113] A propulsion system according to any of the preceding clauses, wherein each of the at least two thrusters further includes a fuel delivery system operably connected to the combustion section, and wherein adjusting the speed of each of the at least two thrusters further includes: adjusting the amount of fuel supplied to the combustion section using the fuel delivery system.

[0114] A propulsion system as described in any preceding clause, wherein the reference phase angle is non-zero.

[0115] A method for operating a propulsion system, the propulsion system comprising at least two propellers, each of the at least two propellers comprising a fan having a plurality of fan blades, the method comprising: determining a paired phase difference between one of the at least two propellers and another of the at least two propellers; generating a reference phase angle different from the paired phase difference; determining a target phase shift for each of the at least two propellers based at least in part on the reference phase angle and the paired phase difference; and adjusting a speed of each of the at least two propellers based on the target phase shift until the paired phase difference equals the reference phase angle.

[0116] A method as in any preceding clause, wherein the target phase shift for each thruster is determined to minimize a cost function.

[0117] A method according to any preceding clause, wherein the at least two thrusters include a first thruster, a second thruster, and a third thruster, wherein the paired phase difference is a first paired phase difference between the first thruster and the second thruster, and wherein the method further comprises: determining a second paired phase difference between the first thruster and the third thruster, and wherein the first paired phase difference is different from the second paired phase difference.

[0118] A method as in any preceding clause, wherein at least one of the at least two thrusters is a digital thruster.

[0119] A method as in any preceding clause, wherein a pairwise phase difference between the digital thruster and at least one other of the at least two thrusters is zero.

[0120] A method according to any preceding clause, wherein the at least two propellers include a first propeller and a second propeller, the first propeller including a first fan having a first plurality of fan blades, the second propeller having a second fan having a second plurality of fan blades, wherein the first propeller defines a first angle between a first top dead center (TDC) reference line and a fan blade of the first plurality of fan blades that is closest to the first TDC reference line at a certain moment, wherein the second propeller defines a second angle between a second TDC reference line and a fan blade of the second plurality of fan blades that is closest to the second TDC reference line at the moment, and wherein the paired phase difference is the difference between the first angle and the second angle at the moment.

[0121] A method according to any preceding clause, wherein each of the at least two propellers further comprises a shaft and a motor operably connected to the shaft, and wherein adjusting the speed of each of the at least two propellers comprises adjusting the rotational speed of the shaft by transferring power between the motor and the shaft.

[0122] A method according to any of the preceding clauses, wherein each of the at least two thrusters further includes a fuel delivery system operably connected to the combustion section, and wherein adjusting the speed of each of the at least two thrusters further includes: adjusting the amount of fuel supplied to the combustion section using the fuel delivery system.

[0123] A method as in any preceding clause, wherein the reference phase angle is non-zero.

[0124] A method as in any preceding clause, wherein the cost function is iteratively minimized by successively testing target phase shift values ​​to converge on a minimum target phase shift for each of the at least two thrusters.

[0125] A controller that communicates with a gas turbine system, the controller comprising a memory and one or more processors, the memory storing instructions that, when executed by the one or more processors, cause the system to perform the following operations: determine a paired phase difference between one of at least two thrusters of the gas turbine system and another of the at least two thrusters; generate a reference phase angle that is different from the paired phase difference; determine a target phase shift for each of the at least two thrusters based at least in part on the reference phase angle and the paired phase difference using a cost function; and instruct the gas turbine system to adjust the speed of each of the at least two thrusters based on the target phase shift until the paired phase difference is equal to the reference phase angle.

[0126] This written description uses examples to disclose the present disclosure, including the best mode, and also enables any person skilled in the art to practice the present disclosure, including making and using any device or system and performing any combined methods. The patent scope of the present disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. If these 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, these other examples are intended to fall within the scope of the claims.

Claims

1. A propulsion system, characterized in that: include: at least two propellers, each of the at least two propellers comprising a fan having a plurality of fan blades; as well as A controller comprising a memory and one or more processors, wherein the memory stores instructions that, when executed by the one or more processors, cause the system to perform the following operations: determining a pairwise phase difference between one of the at least two thrusters and another of the at least two thrusters; generating a reference phase angle different from the pairwise phase difference; determining a target phase shift for each of the at least two thrusters based at least in part on the reference phase angle and the pairwise phase difference; and The speed of each of the at least two thrusters is adjusted based on the target phase shift until the pairwise phase difference equals the reference phase angle.

2. The propulsion system according to claim 1, characterized in that: in, The target phase shift for each thruster is determined so as to minimize a cost function.

3. The propulsion system according to claim 1, characterized in that: in, The at least two thrusters include a first thruster, a second thruster, and a third thruster, wherein the pairwise phase difference is a first pairwise phase difference between the first thruster and the second thruster, and wherein the one or more processors are further configured to: A second pairwise phase difference between the first thruster and the third thruster is determined, and wherein the first pairwise phase difference is different from the second pairwise phase difference.

4. The propulsion system according to claim 1, characterized in that: in, At least one of the at least two thrusters is a digital thruster.

5. The propulsion system according to claim 4, characterized in that in, A pairwise phase difference between the digital thruster and at least one other thruster of the at least two thrusters is zero.

6. The propulsion system according to claim 1, characterized in that in, The at least two propellers include a first propeller and a second propeller, the first propeller including a first fan having a first plurality of fan blades, the second propeller having a second fan having a second plurality of fan blades, wherein the first propeller defines a first angle between a first top dead center (TDC) reference line and a fan blade among the first plurality of fan blades that is closest to the first TDC reference line at a certain moment, wherein the second propeller defines a second angle between a second TDC reference line and a fan blade among the second plurality of fan blades that is closest to the second TDC reference line at the moment, and wherein the paired phase difference is the difference between the first angle and the second angle at the moment.

7. The propulsion system according to claim 1, characterized in that in, Each of the at least two propellers further comprises a shaft and a motor operably connected to the shaft, and wherein adjusting the speed of each of the at least two propellers comprises: The rotational speed of the shaft is regulated by transferring power between the motor and the shaft.

8. The propulsion system according to claim 1, characterized in that in, Each of the at least two thrusters further comprises a fuel delivery system operably connected to the combustion section, and wherein adjusting the speed of each of the at least two thrusters further comprises: An amount of fuel supplied to the combustion section using the fuel delivery system is adjusted.

9. The propulsion system according to claim 1, characterized in that in, The reference phase angle is non-zero.

10. A method of operating a propulsion system, the propulsion system comprising at least two propellers, the at least two propellers each comprising a fan having a plurality of fan blades, characterized in that: The method comprises: determining a pairwise phase difference between one of the at least two thrusters and another of the at least two thrusters; generating a reference phase angle different from the pairwise phase difference; determining a target phase shift for each of the at least two thrusters based at least in part on the reference phase angle and the pairwise phase difference; and The speed of each of the at least two thrusters is adjusted based on the target phase shift until the pairwise phase difference equals the reference phase angle.

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