A hybrid electric propulsion turbofan engine configuration for ultra-high-speed helicopters

Abstract

The present invention relates to a hybrid electric propulsion turbofan engine configuration for a super-high-speed helicopter, and belongs to the field of aircraft power. The configuration disclosed in the present invention includes: a turbofan engine, a power generation system, and a lift electric fan assembly. The turbofan engine includes a linked double annular guide vane device with a continuously adjustable bypass ratio and an adjustable tail nozzle. The double annular guide vane device can be adjusted from 0 to 90 degrees to achieve continuous adjustment of the bypass ratio before and after the fan. The power generation system includes a rectifier and a generator directly driven by a turbine rotor. The lift electric fan assembly includes an inverter, an electric motor, and a lift fan. The present invention coordinates and controls the bypass ratio and the tail nozzle area, closes / opens the outer duct during hovering / cruising, and expands / converges the tail nozzle, so that almost all the energy of the engine is converted into the lift of hovering or the jet thrust of cruising, so that the helicopter can climb vertically to hovering or cruising with maximum capacity, and can continuously and smoothly transition between the two modes.

Description

Technical Field

[0001] The invention relates to a hybrid electric propulsion turbofan engine configuration for a super-high-speed helicopter, belonging to the field of aircraft power. Background Art

[0002] High-tech local wars in the new modern military transformation environment have put forward higher requirements on the performance of helicopters, and there is an urgent need for an ultra-high-speed helicopter that can provide rapid support and agile strikes. The forward rotor blades of conventional helicopters will generate shock waves due to excessive speed, and the backward rotor blades will stall due to excessively low speed, which will reduce the lift of the helicopter and increase the drag, thereby limiting the maximum forward flight speed of the helicopter to within the range of 250 km / h to 350 km / h. In order to increase the flight speed limit of conventional helicopters, the helicopter industry has currently proposed two main solutions:

[0003] One is the tilt-rotor aircraft, which is similar to the fixed-wing aircraft wing tip, each equipped with a set of rotor tilt system components that can rotate freely between horizontal and vertical positions. Although it has a higher cruising speed and longer range than traditional helicopters, such as the V-22 Osprey's maximum speed of 509 kilometers per hour, it still cannot break the 600 kilometers per hour cruising speed of conventional propeller aircraft, indicating that the propeller (i.e., rotatable rotor) propulsion process has a problem of low cruising speed.

[0004] The second is to use a coaxial counter-rotating twin-rotor and propulsion propeller combination structure. The upper and lower sets of coaxial counter-rotating rotors can balance the rotor rolling torque with each other, and no tail rotor structure is required. The tail propulsion propeller can achieve a higher forward flight speed. For example, the maximum flight speed of the S-97 exceeds 482 kilometers per hour. However, for the coaxial counter-rotating twin-rotor solution, since the two propellers rotate in opposite directions, the propeller at the rear will constantly pass through the wake of the front propeller, which will produce a complex dynamic adverse aerodynamic interference, making the overall aerodynamic efficiency of the coaxial counter-rotating propulsion device lower, that is, the engine power required for the propeller under the same thrust increases, and the fuel consumption rate increases, thereby limiting the further increase in flight speed.

[0005] Short Take Off / Vertical Landing (STOVL) aircraft is also a development direction. As a typical short take-off / vertical landing fixed-wing aircraft, F35B is applied to various combat environments due to its excellent assault, reconnaissance and tracking and close air support capabilities. The advanced propulsion system installed on such short take-off / vertical landing fixed-wing aircraft plays a vital role in taking off on a runway and deck of more than 100 meters. In order to achieve a continuous and smooth transition between vertical take-off and landing and cruising, F35B uses a clutch between the engine and the lift fan to achieve switching transition. It is driven by a transmission shaft. Its power is equivalent to the transmission shaft of a destroyer, reaching 28,000 horsepower, and its cross-sectional area is only the size of a washbasin. However, because it is combined with the main shaft and the fan at the same time, there is a huge speed difference between the two. At the moment of engagement, extremely high torque load and temperature will be generated, which puts extremely high requirements on the stable transition and materials of the turbofan engine. It is said that the development team used a particularly wear-resistant carbon material to solve the temperature problem, but how the engine solves the high torque load at the moment of engagement has not been revealed too much, that is, this technology has not yet been mastered in China.

[0006] When ultra-high-speed helicopters break through Mach 0.8, or 980 km / h, no matter whether it is a tilt-rotor solution, such as CN106986020A, or a coaxial counter-rotating twin rotor + propulsion propeller combination solution, such as CN109665096A, or a mixed solution of the two, such as CN108045572A, there are problems of insufficient propeller thrust and excessive rotor tip speed causing shock waves when the speed is broken. The fundamental reason is that it is difficult for both to take into account the high-speed cruising and hovering characteristics of the helicopter in terms of power selection. It is well known that the technology of using turbofan engines to achieve 0.8 Mach cruise is already quite mature, and the technology of using turboshafts to drive rotors or lift fans to achieve aircraft hovering is also mature. However, in terms of aircraft power, when switching between hovering and cruising states, the hovering turbofan air flow is about 4 times that of 0.8 Mach cruise. The compressor of the turbofan engine is very easy to enter surge when working across such a large air flow. This urgently requires the development of corresponding aircraft power to meet the performance requirements of high-speed cruising and hovering, as well as the search for non-clutch solutions to solve the huge torque load and high temperature problems at the moment of engagement. Summary of the invention

[0007] The purpose of the present invention is to provide a hybrid electric propulsion turbofan engine configuration for a super-high-speed helicopter, aiming to develop a power system for a super-high-speed helicopter with a cruising Mach number of about 0.8, using a turbofan engine with continuously adjustable bypass ratio and tail nozzle area, when hovering, switching to a turboshaft mode to drive a lift fan to vertically climb or hover, and when cruising, switching to a turbofan mode for super-high-speed jet propulsion cruise, the two modes can be continuously and smoothly transitioned to solve the problem that the engine is easy to enter surge when working across the two large air flow differences between cruising and hovering, and the switching process does not use a clutch to control the duct fan and the lift fan, thereby solving the problem of extremely large torque load and high temperature at the moment of clutch engagement.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A hybrid electric propulsion turbofan engine configuration for an ultra-high-speed helicopter comprises: a turbofan engine, a power generation system and a lift electric fan assembly. The turbofan engine comprises a linked double annular guide vane device with a continuously adjustable bypass ratio and an adjustable tail nozzle. The double annular guide vane device can be adjusted by 0 to 90 degrees to achieve continuous adjustment of the bypass ratio before and after the fan. The double annular guide vane device can effectively reduce the amount of work done by the fan on the airflow bypassing the front annular guide vane when a single annular guide vane device is used, and the power consumption of the lift fan during takeoff / vertical landing is reduced to the maximum extent, thereby reducing the fuel consumption during hovering. The power generation system comprises a rectifier and a generator directly driven by a turbine rotor, and the lift electric fan assembly comprises an inverter, an electric motor and a lift fan. The turbofan engine is connected to the generator of the power generation system through a rotating shaft, the generator is connected to the rectifier through a wire, and then connected to the inverter through the rectifier. The inverter comprises a plurality of stable power supply channels, and is connected to the lift electric fan assembly through a wire. The plurality of lift fans in the lift electric fan assembly are independently connected to the plurality of stable power supply channels on the inverter.

[0010] The double annular guide vane device comprises a rear guide vane row follower, a rear guide vane row connecting rod ring, a driving device, a rear guide vane row blade, a rear guide vane row rotating rod, a front guide vane row blade, a front guide vane row rotating rod, a front guide vane row follower, a front guide vane row connecting rod ring, and an annular support frame, wherein the annular support frame is used to fix the front guide vane blade root, the driving device comprises a motor, an active member, a parallel connecting rod, and a follower, the rear guide vane row rotating rod is nested in the rear guide vane row blade, and is connected to the rear guide vane row follower through a hinge point, each rear guide vane row follower is hinged in parallel to the rear guide vane row connecting rod ring, wherein a certain rear guide vane row follower is fitted with the active member, the active member is fixedly connected to the motor shaft, and is also connected to the follower through a parallel connecting rod, the follower is fitted with a certain front guide vane row follower, and is constructed for double-row guide vane adjustment of the ducted fan of 0 to 90 degrees, so that a single driving source can be used to continuously adjust the front and rear channels of the fan outer duct from closed to open;

[0011] The motor is an electric drive motor; the double annular guide vane device can be equipped with multiple drive devices;

[0012] A load-bearing guide vane is installed behind the rear guide vane row of blades of the double annular guide vane device, which is configured to support the inner duct rotor and stationary components and guide the circumferential velocity component of the gas flowing out of the outer duct of the double annular guide vane device into an axial direction.

[0013] The hybrid electric propulsion turbofan engine configuration for a super-high-speed helicopter is characterized in that the process of switching between the two modes of the ducted fan of the turbofan engine is as follows:

[0014] ① Cruise state → hovering state: The motor drives the active member to rotate from the 45° position to the -45° position, which corresponds to the double-row guide vanes rotating from the 90° position to the 0° position. At this time, a certain rear guide vane row follower that is in contact with the active member rotates clockwise, and drives the entire rear guide vane row follower to rotate clockwise through the rear guide vane row connecting rod ring, thereby driving the entire rear guide vane row rotating rod to rotate clockwise through the hinge point. When it finally stops, the rear row blades completely close the rear channel of the outer duct; at the same time, the displacement of the motor-driven active member is transmitted to the front guide vane row follower through the parallel connecting rod, which also drives the entire front guide vane rotating rod to rotate clockwise, and finally the front row blades completely close the front channel of the outer duct;

[0015] ② Hovering state → cruising state: the motor drives the active part to rotate from the -45° position to the 45° position, which corresponds to the double-row guide vanes rotating from the 0° position to the 90° position, so that the rotating rods and connecting rod rings of the front guide vane row and the rear guide vane row rotate counterclockwise, and finally the front and rear blades completely close the front and rear channels of the fan outer duct.

[0016] The hybrid electric propulsion turbofan engine configuration for a super high-speed helicopter is characterized in that the configuration is controlled by a flight control system and an engine controller, and includes four working processes: I-starting, II-lift mode, III-lift and cruise transition, and IV-cruise mode. During mode conversion, the pilot manipulates the throttle lever and the working mode switch, the flight control system coordinates the power output of the lift fan motor, and the engine controller coordinates the control of the bypass ratio, the nozzle area, and the fuel flow rate. The specific working process of the super high-speed helicopter is as follows:

[0017] ①I: Turbofan engine, the outer duct is completely closed, the tail nozzle is fully expanded, and the speed is accelerated to the slow speed n idle ;

[0018] ②I→II: The engine controller increases the fuel flow, and the rotor speed changes from the slow speed n idle Accelerate to hovering speed n liftAnd it works at the rated working point A, the outer duct is still completely closed, the airflow can only enter the core engine through the inner duct, and compress, burn, expand and do work on the turbine in the core engine flow passage. The tail nozzle is fully expanded so that the outlet velocity of the inner duct airflow is almost zero, that is, almost no jet propulsion is generated. At this time, the turbine drives the generator to generate electricity through the rotating shaft, and the current converts AC into DC through the rectifier. The DC is converted into constant frequency and constant voltage AC through the inverter to drive multiple lift fans to rotate. The lift fan adopts an expanded lip to increase the hovering air intake. In this mode, almost all the energy of the engine is converted into lift of the lift fan;

[0019] ③II→III→IV: The aircraft accelerates to climb to the corresponding cruise Mach number and altitude. The engine controller accelerates from hovering point A to lift mode switching point B according to the throttle lever command. After that, the engine controller adopts speed closed-loop control with a speed of n switch The controller controls the motor's angular position precisely, and the guide vanes slowly open the front and rear channels of the fan's outer duct. The amount of work done by the ducted fan on the outer ducted gas increases, so the fan load increases. The engine controller increases the fuel flow rate to adapt to the increase in the ducted fan load. At the same time, a small portion of the gas enters the core engine through the inner duct, and is compressed, burned, and expanded in the core engine flow channel to do work on the turbine. The tail nozzle slowly converges from full expansion, and the turbine's ability to do work is weakened. The engine controller increases the fuel flow rate to achieve a constant turbine speed, and the outlet velocity of the inner duct airflow increases, and the jet propulsion force increases. At this time, the flight control system reduces the power output of the lift fan motor, and the lift fan speed decreases. As the flight speed increases, the wing begins to generate lift. When the lift mode switching point B transitions to the cruise switching point C, the duct is fully opened, the tail nozzle is fully converged, the lift fan speed is zero, and the wing lift completely replaces the lift of the lift fan. At this time, the generated electricity is only used to power the internal equipment of the aircraft. Almost all the energy of the engine is converted into the jet propulsion of the aircraft. According to the cruise speed requirement, it accelerates from point C to point D. During this transition process, the total lift remains unchanged, and the propulsion increases slowly to ensure a continuous and smooth transition.

[0020] ④IV→III→II: The engine controller reduces the fuel flow according to the throttle lever command, decelerating from the cruise point D to the cruise switching point C. At this time, the controller begins to slowly close the outer duct and the expansion tail nozzle, and the flight control system accelerates the lift fan. When it finally transitions to the lift mode switching point B, almost all the energy of the engine is converted into the lift of the lift fan, and it decelerates from the lift mode switching point B to point A according to the descent height requirement. During this transition process, the total lift remains unchanged, and the propulsion force slowly decreases to ensure a continuous and smooth transition;

[0021] During the processes of I→II→III→IV and IV→III→II→I, the fuel supply curve of the engine controller is close to the over-temperature surge boundary line, thereby giving full play to the performance potential of the engine;

[0022] The III-mode switching process adopts speed closed-loop control, the steady-state value of the air flow of the inner core engine remains unchanged, and the steady-state value of the core engine compressor pressure ratio remains unchanged.

[0023] The hybrid electric propulsion turbofan engine configuration for a super-high-speed helicopter is characterized in that the turbofan engine is connected to the generator through a rotating shaft, the turbofan engine is a single rotor, or a dual rotor, or a triple rotor, and the generator selects the connecting shaft based on the principle of compact installation, whether it is a low-pressure shaft or a high-pressure shaft of a dual rotor, or a low-pressure shaft, a medium-pressure shaft or a high-pressure shaft of a triple rotor, and the connecting part is an extended shaft or an intermediate shaft at both ends of the shaft. For example, for a single-rotor engine, the scheme that can be adopted is:

[0024] ① A rotating shaft is led out from the front of the fan cover of the turbofan engine and connected to the generator shaft;

[0025] ② Install a generator in the chamber between the fan and compressor of the turbofan engine;

[0026] ③ A rotating shaft is led out from the tail of the turbofan engine's turbine and connected to the generator shaft.

[0027] Compared with the prior art, the advantages of the present invention are as follows: the present invention develops a power system for an ultra-high-speed helicopter with a cruising Mach number of about 0.8, and by coordinating the control of the front-to-rear bypass ratio of the duct fan, the tail nozzle area, the fuel flow rate and the lift fan motor power, the power consumption of the turbofan engine in the hovering state can be reduced to the maximum extent. When hovering / cruising, the outer duct is closed / opened, the tail nozzle expands / converges, and the lift fan rotates at full speed / does not rotate, so that almost all energy is converted into the lift for hovering or the propulsion for cruising, and finally the helicopter can climb vertically to hover at maximum capacity and cruise at high speed at maximum capacity, and the two modes can be continuously and smoothly transitioned, and the fuel supply curves of the turbofan engine of the present invention are close to the super-temperature and surge boundaries, so that the design gives full play to the performance potential of the engine. Compared with the turbofan engine with non-adjustable outer duct, the present invention widens the stable working range, so that this power system can work stably under the two major working conditions of hovering and cruising. Compared with the engine with a clutch, the present invention does not have the problem of extremely large torque load and extremely high temperature when the mode is switched. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the operation of the entire power system of the present invention in cruise and lift modes.

[0029] Figure 2Detailed Description of the Invention The ducted fan of the present invention is shown in a stereoscopic view, a front view and a left view in a cruise mode and a lift mode respectively.

[0030] Figure 3 A schematic diagram of the fan and compressor chamber installation scheme for the generator layout of the single-rotor turbofan of the present invention.

[0031] Figure 4 It is the fuel supply-speed variation curve of the turbofan engine of the present invention in different modes.

[0032] Figure 5 It is the parameter change curve of the turbofan engine modal conversion transition process of the present invention.

[0033] Figure 6 It is the change curve of control parameters and performance parameters of the entire power system mode conversion transition process of the present invention.

[0034] In the figure: 1-rear guide vane row follower, 2-rear guide vane row connecting rod ring, 3-front guide vane row follower, 4-front guide vane row connecting rod ring, 5-driving device, 51-motor, 52-active member, 53-parallel connecting rod, 54-follower, 61-rear guide vane row blades, 62-rear guide vane row rotating rod, 71-front guide vane row blades, 72-front guide vane row rotating rod, 8-annular support frame, 9-load-bearing guide vanes, A-hovering point, B-lift mode switching point, C-cruise switching point, D-cruise point. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] See also Figure 1In an embodiment of the present invention, a hybrid electric propulsion turbofan engine configuration for a super-high-speed helicopter includes: a turbofan engine, a power generation system and a lift electric fan assembly. The turbofan engine includes a linked double annular guide vane device with a continuously adjustable bypass ratio and an adjustable tail nozzle. The double annular guide vane device can be adjusted from 0 to 90 degrees to achieve continuous adjustment of the bypass ratio before and after the fan. Compared with a single-ring guide vane device, the double annular guide vane device can effectively reduce the amount of airflow bypassing the front ring guide vane to allow the fan to do work on it, thereby minimizing the power consumption of the lift fan during takeoff / vertical landing, thereby reducing the fuel consumption during hovering. The power generation system includes a rectifier and a generator directly driven by a turbine rotor. The lift electric fan assembly includes an inverter, an electric motor and a lift fan. The turbofan engine is connected to a generator of the power generation system through a rotating shaft, the generator is connected to the rectifier through a wire, and then connected to the inverter through the rectifier. The inverter includes four stable power supply channels and is connected to the lift electric fan assembly through a wire. The four lift fans in the lift electric fan assembly are independently connected to multiple stable power supply channels on the inverter.

[0037] See also Figure 2 In the embodiment of the present invention, the double annular guide vane device includes a rear guide vane row follower 1, a rear guide vane row connecting rod ring 2, a driving device 5, a rear guide vane row blade 61, a rear guide vane row rotating rod 62, a front guide vane row blade 71, a front guide vane row rotating rod 72, a front guide vane row follower 3, a front guide vane row connecting rod ring 4, and an annular support frame 8, wherein the annular support frame 8 is used to fix the front guide vane row blade root, the driving device 5 includes a motor 51, an active member 52, a parallel connecting rod 53, and a driven member 54, and the rear guide vane row rotating rod 62 is nested in the rear guide vane row blade 6 1, and connected with the rear guide vane row follower 1 through a hinge point, each rear guide vane row follower 1 is parallelly hinged on the rear guide vane row connecting rod ring 2, wherein a certain rear guide vane row follower is fitted with the active member 52, the active member 52 is fixedly connected to the rotating shaft of the motor 51, and is also connected with the follower 54 through a parallel connecting rod 53, the follower 54 is fitted with a certain front guide vane row follower, and is constructed for double-row guide vane adjustment of the ducted fan at 0 to 90 degrees, and can realize continuous adjustment of the front and rear channels of the fan outer duct from closed to open with a single driving source;

[0038] The motor 51 should be convenient for hybrid electric propulsion system when implemented, using an electric drive motor without the need for an oil pressure source;

[0039] The double annular guide vane device is specifically implemented with two devices installed on the left and right to meet the power requirements for stable operation of the device;

[0040] A load-bearing guide vane 9 is installed behind the rear guide vane row blades 61 of the double annular guide vane device to support the inner duct rotor and stationary parts and guide the circumferential velocity component of the gas flowing out of the outer duct of the double annular guide vane device into an axial direction.

[0041] See also Figure 2 In an embodiment of the present invention, a hybrid electric propulsion turbofan engine configuration for a super high-speed helicopter is characterized in that the process of switching between the two modes of the ducted fan of the turbofan engine is:

[0042] ① Cruise state → hovering state: the motor 51 drives the active member 52 to rotate from the 45° position to the -45° position, which corresponds to the double-row guide vanes rotating from the 90° position to the 0° position. At this time, a certain rear guide vane row follower in contact with the active member 52 rotates clockwise, and drives the entire rear guide vane row follower 1 to rotate clockwise through the rear guide vane row connecting rod ring 2, thereby driving the entire rear guide vane row rotating rod 62 to rotate clockwise through the hinge point. When it finally stops, the rear row blades completely close the rear channel of the outer duct; at the same time, the motor 51 drives the displacement of the active member 52 to be transmitted to the front guide vane row follower 3 through the parallel connecting rod 53, and also drives the entire front guide vane rotating rod 62 to rotate clockwise. Finally, the front row blades also completely close the front channel of the outer duct, thereby minimizing the power consumption of the lift fan during takeoff / vertical landing;

[0043] ② Hovering state → cruising state: the motor 51 drives the active component 52 to rotate from the -45° position to the 45° position, which corresponds to the double-row guide vanes rotating from the 0° position to the 90° position, and finally makes the rotating rods and connecting rod rings of the front guide vane row and the rear guide vane row rotate counterclockwise, and finally the front row blades and the rear row blades completely open the front and rear channels of the fan outer duct.

[0044] See also Figure 4 In an embodiment of the present invention, a hybrid electric propulsion turbofan engine configuration for a super high-speed helicopter is characterized in that the configuration is controlled by a flight control system and an engine controller, and includes four working processes: I-starting, II-lift mode, III-lift and cruise transition, and IV-cruise mode. During mode conversion, the pilot manipulates the throttle lever and the working mode switch, the flight control system coordinates the power output of the lift fan motor, and the engine controller coordinates the control of the bypass ratio, the nozzle area, and the fuel flow rate. The specific working process of the super high-speed helicopter is as follows:

[0045] ①I: Turbofan engine, the outer duct is completely closed, the tail nozzle is fully expanded, and the speed is accelerated to the slow speed n idle ;

[0046] ②I→II: The engine controller increases the fuel flow, and the rotor speed changes from the slow speed n idle Accelerate to hovering speed n liftAnd it works at the rated working point A, the outer duct is completely closed, the airflow can only enter the core engine through the inner duct, and is compressed, burned, expanded and works on the turbine in the core engine flow passage. The tail nozzle is fully expanded so that the outlet velocity of the inner duct airflow is almost zero, that is, almost no jet propulsion is generated. At this time, the turbine drives the generator to generate electricity through the rotating shaft, and the current is converted from AC to DC through the rectifier. The DC is converted into constant frequency and constant voltage AC through the inverter to drive multiple lift fans to rotate. The lift fan adopts an expanded lip to increase the hovering air intake. In this mode, almost all the energy of the engine is converted into lift of the lift fan;

[0047] ③II→III→IV: The aircraft accelerates to climb to the corresponding cruise Mach number and altitude. The engine controller accelerates from hovering point A to lift mode switching point B according to the throttle lever command. After that, the engine controller adopts speed closed-loop control with a speed of n switch The controller controls the angular position of the motor 51 precisely, and the guide vanes slowly open the front and rear channels of the fan outer duct. The work done by the ducted fan on the outer ducted gas increases, so the fan load increases. The engine controller increases the fuel flow rate to adapt to the increase in the ducted fan load. At the same time, a small part of the gas enters the core engine through the inner duct, and is compressed, burned, expanded and works on the turbine in the core engine flow channel. The tail nozzle slowly converges from full expansion, and the turbine's work capacity is weakened. The engine controller increases the fuel flow rate to achieve a constant speed of the turbine, and the outlet velocity of the inner duct airflow increases, and the jet propulsion force increases. At this time, the flight control system reduces the power output of the lift fan motor, and the lift fan speed decreases. As the flight speed increases, the wing begins to generate lift. When the lift mode switching point B transitions to the cruise switching point C, the duct is fully opened, the tail nozzle is fully converged, the lift fan speed is zero, and the wing lift completely replaces the lift of the lift fan. At this time, the generated electricity is only used to power the internal equipment of the aircraft. Almost all the energy of the engine is converted into the jet propulsion of the aircraft. According to the cruise speed requirement, it accelerates from point C to point D. During this transition process, the total lift remains unchanged, and the propulsion increases slowly to ensure a continuous and smooth transition.

[0048] ④IV→III→II: The engine controller reduces the fuel flow according to the throttle lever command, decelerating from the cruise point D to the switching point C. At this time, the controller begins to slowly close the outer duct and the expansion tail nozzle, and the flight control system accelerates the lift fan. Finally, when the engine transitions to the lift mode switching point B, almost all the energy of the engine is converted into the lift of the lift fan, and it decelerates from point B to point A according to the descent height requirement. During this transition process, the total lift remains unchanged, and the propulsion force slowly decreases to ensure a continuous and smooth transition;

[0049] In the processes II→III→IV (ABCD) and IV→III→II (DCBA), the fuel supply curves of the engine controller are close to the unstable boundary, that is, the overheating and surge boundary. This design gives full play to the performance potential of the engine, and compared with the turbofan engine with non-adjustable outer duct, the present invention broadens the stable working range of the turbofan engine, so that the power system can work stably under the two major working conditions of hovering and cruising.

[0050] See also Figure 5 In the embodiment of the present invention, the III-mode switching process adopts a speed closed-loop control, the steady-state value of the air flow of the core engine remains unchanged, and the steady-state value of the core engine compressor pressure ratio remains unchanged. During the III-lift and cruise transition process, the pilot pushes the throttle lever from the lift mode throttle lever position PLA at time t0 lift Push the throttle lever to the cruise mode position PLA cruise Due to the hysteresis of the fuel regulating mechanism response, the turbofan engine fuel flow W at time t1 is f The turbofan engine adopts closed-loop speed control, which contains the speed n of the core engine. switch The steady-state value remains unchanged, and the compressor pressure ratio π * C The steady-state value remains unchanged. From time t2, the bypass ratio a is slowly increased using ramp increment control. The core engine speed n switch and compressor pressure ratio π * C Jitter will occur.

[0051] See also Figure 6 In the embodiment of the present invention, the power system controls the fuel flow W f , ducted fan front and rear bypass ratio a, tail nozzle area A8 and lift fan power P fan The coordinated control of the lift fan lift L of the ultra-high-speed helicopter is realized fan Alternative wing lift L wing The total lift L during the process total unchanged, in the turbofan jet propulsion force F duct Replacement lift fan front F fan During the process, the propulsion force F of the power system total Increase slowly to achieve coordinated control, and the mode switching time is as short as possible. The specific control process is: at time t1, the turbofan engine fuel flow W f The flight control system starts to increase. At this time, the flight control system controls multiple lift fans to achieve the forward flight of the ultra-high-speed helicopter. The ultra-high-speed helicopter has a small forward flight angle of attack, and the lift fan generates a propulsion force of F fanFrom t1 to t2, the lift fan power increases slowly using the ramp increment control mode. At t2, the lift fan power begins to decrease using the negative acceleration increment control. The super-high-speed helicopter slowly reduces the forward flight angle of attack, and the turbofan engine begins to generate jet propulsion force F duct , and at t3 the jet thrust F duct Completely replaces fan propulsion F fan , the entire process from t1 to t2 F total Slowly increase, the total lift L total Constant.

[0052] See also Figure 1 and Figure 3 In an embodiment of the present invention, a hybrid electric propulsion turbofan engine configuration for a super-high-speed helicopter is characterized in that the turbofan engine is connected to the generator through a rotating shaft, the turbofan engine is a single rotor, or a dual rotor, or a triple rotor, and the generator selects the connected shaft based on the principle of compact installation, whether it is a low-pressure shaft or a high-pressure shaft of a dual rotor, or a low-pressure shaft, a medium-pressure shaft, or a high-pressure shaft of a triple rotor, and the connection part is an extended shaft at both ends of the shaft or an intermediate shaft. When implemented specifically, a single rotor solution is adopted, and the generator layout that can be adopted is:

[0053] ① A rotor shaft extends from the front of the fan cover of the turbofan engine and is connected to the generator shaft;

[0054] ② Install a generator in the chamber between the fan and compressor of the turbofan engine;

[0055] ③ A rotor shaft extends from the tail of the turbofan engine's turbine and is connected to a generator shaft.

[0056] The present invention is not limited to the above-mentioned embodiments. On the basis of the technical solution disclosed in the present invention, technicians in this field can make some simple modifications, equivalent changes and modifications to some of the technical features therein according to the disclosed technical content without creative labor, all of which belong to the scope of the technical solution of the present invention.

Claims

1. A hybrid electric propulsion turbofan engine configuration for a very high speed helicopter, comprising: A turbofan engine, a power generation system and a lift electric fan assembly, wherein the turbofan engine comprises a linked double annular guide vane device with continuously adjustable bypass ratio and an adjustable tail nozzle, wherein the double annular guide vane device can be adjusted from 0 to 90 degrees to achieve continuous adjustment of the bypass ratio before and after the fan, wherein the power generation system comprises a rectifier and a generator directly driven by a turbine rotor, and wherein the lift electric fan assembly comprises an inverter, an electric motor and a lift fan; wherein the turbofan engine is connected to the generator of the power generation system via a rotating shaft, wherein the generator is connected to the rectifier via a wire, and then to the inverter via the rectifier, wherein the inverter comprises a plurality of power supply channels, and is connected to the lift electric fan assembly via a wire, wherein the plurality of lift fans therein are independently connected to the plurality of power supply channels on the inverter; The double annular guide vane device comprises a rear guide vane row follower (1), a rear guide vane row connecting rod ring (2), a driving device (5), a rear guide vane row blade (61), a rear guide vane row rotating rod (62), a front guide vane row blade (71), a front guide vane row rotating rod (72), a front guide vane row follower (3), a front guide vane row connecting rod ring (4), and an annular support frame (8); the driving device (5) comprises a motor (51), an active member (52), a parallel connecting rod (53), and a follower (54); the rear guide vane row rotating rod (62) is nested in the rear guide vane row blade (61), and is connected to the rear guide vane row blade (61). The rear guide vane row follower (1) is connected via a hinge point, and each rear guide vane row follower (1) is hinged in parallel to the rear guide vane row connecting rod ring (2), wherein a certain rear guide vane row follower is fitted with an active member (52), and the active member (52) is fixedly connected to the rotating shaft of the motor (51), and is also connected to a follower (54) via a parallel connecting rod (53), and the follower (54) is fitted with a certain front guide vane row follower, and is configured to adjust the bypass ratio of the double-row guide vanes of the ducted fan at 0 to 90 degrees, so that the bypass ratio of the fan can be continuously adjusted from zero to maximum with a single driving source; The motor (51) is an electric drive motor; the double annular guide vane device can be equipped with multiple drive devices (5); A load-bearing guide vane (9) is installed behind the rear guide vane row blades (61) of the double annular guide vane device, and is configured to support the inner duct rotor and stationary components and guide the circumferential velocity component of the gas flowing out of the outer duct of the double annular guide vane device into an axial direction.

2. A hybrid electric propulsion turbofan engine configuration for a super high speed helicopter as claimed in claim 1, characterized in that: The ducted fan of a turbofan engine includes lift mode and cruise mode. The process of switching between the two modes is as follows: ① Cruise mode → lift mode: the motor (51) drives the active member (52) to rotate from the 45° position to the -45° position, which corresponds to the double-row guide vanes rotating from the 90° position to the 0° position. At this time, a certain rear guide vane row follower in contact with the active member (52) rotates clockwise, and drives the entire rear guide vane row follower (1) to rotate clockwise through the rear guide vane row connecting rod ring (2). At the same time, the displacement of the active member (52) driven by the motor (51) is transmitted to the front guide vane row follower (3) through the parallel connecting rod (53), and synchronously drives the entire rear guide vane row rotating rod (62) and the front guide vane rotating rod (62) to rotate clockwise through the hinge point. Finally, the front and rear rows of blades completely close the front and rear channels of the outer duct; ② Lift mode → Cruise mode: The motor (51) drives the active member (52) to rotate from the -45° position to the 45° position, which corresponds to the double-row guide vanes rotating from the 0° position to the 90° position, so that the rotating rods and connecting rod rings of the front guide vane row and the rear guide vane row rotate counterclockwise, and finally the front and rear blades completely open the front and rear channels of the fan outer duct.

3. A hybrid electric propulsion turbofan engine configuration for a super high speed helicopter as claimed in claim 1, characterized in that: The configuration is controlled by the flight control system and the engine controller, and includes four working processes: I-starting, II-lift mode, III-lift and cruise transition, and IV-cruise mode. During the mode conversion, the pilot operates the throttle lever and the working mode switch, the flight control system coordinates the power output of the lift fan motor, and the engine controller coordinates the control of the bypass ratio, nozzle area and fuel flow. The specific working process of the super high-speed helicopter is as follows: ①I: The outer duct of the turbofan engine is completely closed, the tail nozzle is fully expanded, and the speed is accelerated to the slow speed n idle ; ②I→II: The engine controller increases the fuel flow, and the rotor speed changes from the slow speed n idle Accelerate to lift mode speed n lift And it works at the rated working point A, the outer duct is still completely closed, the airflow can only enter the core engine through the inner duct, and compress, burn, expand and do work on the turbine in the core engine flow passage. The tail nozzle is fully expanded so that the outlet velocity of the inner duct airflow is almost zero, that is, almost no jet propulsion is generated. At this time, the turbine drives the generator to generate electricity through the rotating shaft, and the current converts AC into DC through the rectifier. The DC is converted into constant frequency and constant voltage AC through the inverter to drive multiple lift fans to rotate. The lift fan adopts an expanded lip to increase the hovering air intake. In this mode, almost all the energy of the engine is converted into lift of the lift fan; ③II→III→IV: The aircraft accelerates to climb to the corresponding cruise Mach number and altitude. The engine controller accelerates from hovering point A to lift mode switching point B according to the throttle lever command. After that, the engine controller adopts speed closed-loop control with a speed of n switch The controller controls the motor (51) with precise angular position, and the guide vanes slowly open the front and rear channels of the fan outer duct. The work done by the duct fan on the outer duct gas increases, so the fan load increases. The engine controller increases the fuel flow rate to adapt to the increase in the duct fan load. At the same time, a small part of the gas enters the core engine through the inner duct, and expands in the core engine flow channel through thermal circulation to do work on the turbine. The tail nozzle slowly converges from full expansion, and the turbine work capacity is weakened. The engine controller increases the fuel flow rate to control the turbine speed to be constant. The outlet speed of the inner duct airflow increases, and the jet propulsion force increases. At this time, the flight control system reduces the power output of the lift fan motor, and the lift of the lift fan decreases. As the flight speed increases, the wing begins to generate lift. When the lift mode switching point B transitions to the cruise switching point C, the outer duct is fully opened, the tail nozzle is fully converged, the lift fan speed is zero, and the wing lift completely replaces the lift of the lift fan. Almost all the energy of the engine is converted into the jet propulsion force of the aircraft, and it accelerates from point C to point D according to the cruise speed requirement. During this transition process, the total lift remains unchanged, and the propulsion force slowly increases. ④IV→III→II: The engine controller reduces the fuel flow rate and decelerates from the cruise point D to the switching point C. After that, the controller begins to slowly close the outer duct and the expansion tail nozzle, and the flight control system accelerates the lift fan. Finally, when the engine transitions to the lift mode switching point B, almost all the energy of the engine is converted into the lift of the lift fan, and it decelerates from point B to point A according to the descent height requirement. The transition process needs to ensure that the total lift remains unchanged and the propulsion force is slowly reduced; During the processes of I→II→III→IV and IV→III→II→I, the fuel supply curve of the engine controller is close to the over-temperature surge boundary line, thereby giving full play to the performance potential of the engine; During the III-mode switching process, the air flow of the core engine remains unchanged, and the pressure ratio of the core engine compressor remains unchanged.

4. A hybrid electric propulsion turbofan engine configuration for a super high speed helicopter as claimed in claim 1, characterized in that: The turbofan engine is connected to the generator through a rotating shaft. The turbofan engine is a single rotor, a dual rotor, or a triple rotor. The generator selects the connecting shaft based on the principle of compact installation, whether it is the low-pressure shaft or the high-pressure shaft of the dual rotor, or the low-pressure shaft, the intermediate-pressure shaft, or the high-pressure shaft of the triple rotor; The connection parts are at both ends or in the middle of the shaft.

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