A high-efficiency heat protection combined heat cycle engine and a control method thereof

Abstract

The application relates to the technical field of aero-engines, and discloses a combined engine with a high-efficiency thermal protection mixed thermodynamic cycle and a control method thereof. The combined engine is composed of an external rotating detonation engine and an internal turbine engine. Mode switching of the combined engine is realized through an inlet adjusting valve and an adjustable tail nozzle. The combined engine can effectively connect the upper limit of the turbine engine, complete power relay, cross the thrust gap, has relatively low structural design complexity, and has high system stability. In the afterburning rotating detonation mode, the combustible mixture sprayed by the rotating detonation engine is guided into the afterburning chamber of the turbine engine through an afterburning chamber guide valve to realize detonation combustion, the original cooling device of the afterburning chamber is used for thermal protection, and the outer casing is prevented from being damaged due to high temperature.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of aero-engines and discloses a high-efficiency thermal protection mixed thermodynamic cycle combined engine and a control method thereof. BACKGROUND

[0002] The existing engines capable of flying in a wide speed range mainly include a turbo-ram combined engine, a turbo-ram-rocket combined engine and a turbo-precooling combined engine, and the disadvantages of the engines are as follows.

[0003] (1) When the existing turbo-ram combined power engine crosses the thrust trap, the ram engine needs to work above Ma3 because the lower limit of the ram engine is high (generally above Ma3), and the turbo engine generally works at Ma2.0, so the combined power mode conversion is difficult, the thrust gap interval of Ma2.0-Ma3 cannot be crossed, and the problem of "the turbo engine cannot work above Ma3 and the ram engine cannot work below Ma3" exists.

[0004] (2) The existing turbo-ram-rocket combined engine relies on rocket power assistance, and theoretically can effectively suture the working interval of the turbo and ram power units, complete the mode conversion process and cross the thrust gap, but the introduction of the rocket power greatly increases the design complexity of the combined engine structure and control law, and the engineering application is difficult.

[0005] (3) The existing turbo-precooling combined engine relies on the pre-cooler to cool the high-temperature airflow at the inlet of the compressor when flying at a high Mach number, which avoids the thrust gap in principle, so that the turbo engine can work normally above Ma3, but the pre-cooling unit is heavy, and the coupled control with the power unit is difficult, which greatly increases the design complexity of the combined power structure and control law, and the engineering application is difficult. SUMMARY

[0006] The application aims to provide a high-efficiency thermal protection mixed thermodynamic cycle combined engine and a control method thereof, which can effectively connect the upper limit of the turbo engine, complete power relay, cross the thrust gap, have relatively low structural design complexity, have high system stability and can solve the problem of thermal protection.

[0007] In order to achieve the above technical effects, the application adopts the following technical scheme:

[0008] A high-efficiency thermal protection mixed thermodynamic cycle combined engine, comprising an outer casing, an inner casing and an outer channel between the outer casing and the inner casing, and further comprising:

[0009] A rotary detonation engine arranged in the outer channel.

[0010] a turbine engine disposed in the inner casing;

[0011] a modal switching device comprising an inlet regulation valve, an afterburner guide valve and an adjustable nozzle;

[0012] wherein the inlet regulation valve is disposed at the front end of the inner casing and at the inlet of the outer duct, for regulating the ratio of the intake flow of the outer duct and inner duct;

[0013] the adjustable nozzle is mounted at the tail of the inner casing, the area between the adjustable nozzle and the outer casing constitutes the outer duct of the rotary detonation engine, the area inside the adjustable nozzle constitutes the inner duct of the turbine engine, the adjustable nozzle is used to regulate the ratio of the outlet area of the outer duct and inner duct;

[0014] the afterburner guide valve is disposed on the inner casing, a turbine component of the turbine engine and the adjustable nozzle are provided with an afterburner, the afterburner guide valve is used to form a guide channel when it is opened, to close the flow channel of the turbine engine, while guiding the combustible mixture injected by the rotary detonation engine into the afterburner for detonation combustion.

[0015] Further, the rotary detonation engine comprises a detonation injection structure disposed in the outer duct; the area from the inlet of the outer duct to the front end of the detonation injection structure is a detonation ramjet duct; the rear end of the detonation injection structure is an outer rotary detonation combustion chamber, which is in communication with the outer exhaust duct.

[0016] Further, the inner casing comprises a front casing section and a rear casing section, the afterburner guide valve comprises an adjustable inner wall and an adjustable outer wall, one end of the adjustable inner wall is hinged to the front casing section, one end of the adjustable outer wall is hinged to the rear casing section, the adjustable inner wall and the adjustable outer wall are used to form a structure connecting the front casing section and the rear casing section when they are closed, and form a guide channel when they are opened, to close the flow channel of the turbine engine, while guiding the combustible mixture injected by the rotary detonation engine into the afterburner for detonation combustion.

[0017] A control method of a high-efficiency thermal protection hybrid thermodynamic cycle combined engine, for controlling the aforementioned high-efficiency thermal protection hybrid thermodynamic cycle combined engine, comprising:

[0018] when the operating speed of the combined engine is less than or equal to a first speed threshold, controlling the inlet regulation valve to close the outer duct, the adjustable nozzle to close the outer exhaust duct, the rotary detonation engine to shut down, the intake flow to enter the inner duct, the turbine engine to operate, and the combined engine to be in turbine mode;

[0019] When the operating speed of the combined engine is between the first speed threshold and the second speed threshold, and the first speed threshold is less than the second speed threshold, the inlet regulating valve is controlled to open the bypass duct, the adjustable tail nozzle opens the bypass exhaust duct, the rotating detonation engine and the turbine engine operate simultaneously, and the combined engine is in a transition mode.

[0020] When the flight speed is between the second speed threshold and the third speed threshold, and the second speed threshold is less than the third speed threshold, the inlet regulating valve is controlled to close the inner duct, and at the same time the adjustable tail nozzle closes the inner exhaust duct of the turbine engine, the rotating detonation engine is running, the turbine engine is shut down, and the combined engine is in the rotating detonation mode.

[0021] When the flight speed is greater than or equal to the third speed threshold, the inlet regulating valve is controlled to close the inner duct, the adjustable inner wall and adjustable outer wall of the afterburner guide valve open to form a guide channel, the rotary detonation engine operates, and the combined engine is in afterburning rotary detonation mode; wherein the adjustable inner wall closes the inner exhaust duct of the turbine engine, the adjustable outer wall blocks the outer exhaust duct, and the guide channel guides the combustible mixture ejected by the rotary detonation engine to the afterburner for detonation combustion;

[0022] Specifically, based on the flight state of the combined engine, when the combined engine is in turbine mode, transition mode, and rotating detonation mode, a preset linkage mechanism between the inlet regulating valve and the adjustable tail nozzle is used to adjust the intake flow ratio of the outer bypass duct and the inner duct, while simultaneously adjusting the outlet area ratio of the outer bypass exhaust duct and the inner exhaust duct.

[0023] Furthermore, the method for determining the preset linkage mechanism between the inlet regulating valve and the adjustable tail nozzle is as follows:

[0024] Based on the combined engine's dimensional parameters, a finite element analysis model of the combined engine is constructed.

[0025] The finite element analysis model was used to simulate and analyze the total pressure at the inlet of the bypass exhaust duct, the total temperature at the inlet of the bypass exhaust duct, and the minimum throat area required by the bypass exhaust duct under different flight conditions and different combinations of inlet regulating valve angles.

[0026] Based on the environmental back pressure under each flight state and the total inlet pressure of the bypass exhaust duct under the corresponding combination of conditions, the maximum Mach number of the outlet airflow of the bypass exhaust duct under the corresponding combination of conditions is obtained.

[0027] Based on the minimum throat area and the maximum Mach number, the outlet area of ​​the outer bypass exhaust duct under the corresponding combination conditions is obtained through analysis.

[0028] Using the inlet regulating valve angle, total inlet pressure of the bypass exhaust duct, total inlet temperature of the bypass exhaust duct, and maximum Mach number of the airflow at the outlet of the bypass exhaust duct under each combination condition as inputs, and the outlet area of ​​the bypass exhaust duct under the corresponding combination condition as output, an analysis function for the outlet area of ​​the bypass exhaust duct based on the inlet regulating valve angle is constructed.

[0029] Based on the total inlet pressure, total inlet temperature, and maximum Mach number of the outlet airflow of the combined engine under the state to be analyzed, as well as the required outlet area of ​​the outlet exhaust duct, the inlet regulating valve angle value under the state to be analyzed is obtained by using the analysis function.

[0030] Based on the inlet regulating valve angle value under the state to be analyzed and the required exhaust outlet area of ​​the outer bypass, the inlet regulating valve and the adjustable tail nozzle are controlled to operate.

[0031] Furthermore, the minimum throat area required for the outer bypass exhaust duct is determined by... Analysis yielded, among which, The exhaust outlet area of ​​the duct under the corresponding combination conditions. To design the intake coefficient, air density, For intake speed, The total temperature at the inlet of the duct exhaust pipe. The radius of the outer casing. Let be the radius of the inner casing. The length of the inlet regulating valve, The angle of the inlet regulating valve relative to the radial section of the combined engine. To design the flow coefficient, The total pressure at the inlet of the duct exhaust duct. To design specific flow density.

[0032] Furthermore, the maximum Mach number of the exhaust gas flow at the bypass duct outlet under the corresponding combination conditions is determined by... Analysis yielded, among which, The maximum Mach number of the airflow at the exhaust outlet of the bypass duct. To design the specific heat ratio, The total pressure at the inlet of the duct exhaust duct. This corresponds to the environmental back pressure during flight.

[0033] Furthermore, the analysis function for the outlet area of ​​the bypass exhaust duct based on the inlet regulating valve angle is:

[0034] ,

[0035] in, The outlet area of ​​the external duct exhaust duct is given. To design the intake coefficient, air density, For intake speed, The total temperature at the inlet of the duct exhaust pipe. The radius of the outer casing. Let be the radius of the inner casing. The length of the inlet regulating valve, The angle of the inlet regulating valve relative to the radial section of the combined engine. To design the flow coefficient, The total pressure at the inlet of the duct exhaust duct. To design specific flow density, The maximum Mach number of the airflow at the exhaust outlet of the bypass duct. To design the specific heat ratio.

[0036] Compared with the prior art, the beneficial effects of this invention are:

[0037] This invention employs a combined engine consisting of an external rotary detonation engine and an internal turbine engine. The combined engine achieves mode switching through an inlet regulating valve and an adjustable tail nozzle, effectively connecting the turbine engine's operating limit and completing power relay, thereby bridging the thrust gap. The structural design complexity is relatively low, and the system stability is high. Moreover, in the afterburning rotary detonation mode, the combustible mixture ejected from the rotary detonation engine is guided to the afterburning combustion chamber of the turbine engine through the afterburning combustion chamber guide valve for detonation combustion. The original cooling device of the afterburning combustion chamber is used for thermal protection, preventing damage to the outer casing due to high temperature. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the combined engine in the embodiment;

[0039] Figure 2 for Figure 1 Enlarged schematic diagram of the flow guide valve in the afterburner chamber at point B in the middle section;

[0040] Figure 3 This is a schematic diagram of the combined engine in turbine mode in the embodiment;

[0041] Figure 4 This is a schematic diagram of the combined engine in the transition mode in the embodiment;

[0042] Figure 5 This is a schematic diagram of the combined engine in the rotating detonation mode in the embodiment;

[0043] Figure 6 This is a schematic diagram of the combined engine in the embodiment under afterburning rotational detonation.

[0044] Among them, 10-rotary detonation engine, 11-detonation ramjet duct, 12-detonation injection structure, 13-outer duct rotary detonation combustion chamber, 14-outer duct exhaust duct, 20-turbine engine, 21-intake cone, 22-inner duct exhaust duct, 23-afterburner, 31-outer casing, 32-inner casing, 41-inlet regulating valve, 42-regulating valve actuation mechanism, 43-adjustable tail nozzle, 44-nozzle actuation mechanism, 50-afterburner guide valve, 51-adjustable inner wall, 52-adjustable outer wall. Detailed Implementation

[0045] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0046] Example

[0047] See Figures 1-6 This embodiment provides a high-efficiency thermally protected hybrid thermodynamic cycle combined engine, including an outer casing 31 and an inner casing 32, and an outer bypass duct between the outer casing 31 and the inner casing 32. The combined engine further includes:

[0048] A rotary detonation engine 10 is disposed within the outer duct. The rotary detonation engine 10 includes a detonation ramjet duct 11, a detonation injection structure 12, and an outer duct rotary detonation combustion chamber 13. The detonation ramjet duct 11, the detonation injection structure 12, and the outer duct rotary detonation combustion chamber 13 are all disposed within the outer duct, and the outer duct rotary detonation combustion chamber 13 is connected to the outer duct exhaust duct 14.

[0049] A turbine engine 20 is disposed in the inner casing 32. The turbine engine 20 is provided with an intake cone 21 extending to the intake duct. The area between the intake cone 21 and the front end of the inner casing 32 is the inner duct inlet.

[0050] The mode switching device includes an inlet regulating valve 41, an afterburner flow guide valve 50, and an adjustable tail nozzle 43;

[0051] The inlet regulating valve 41 is located at the front end of the inner casing 32 and at the inlet of the outer bypass duct, and is used to regulate the air intake flow ratio between the outer bypass duct and the inner casing.

[0052] The afterburner flow guide valve 50 is provided on the inner casing 32 and located in the afterburner 23 of the turbine engine 20. The afterburner flow guide valve 50 is used to form a guide channel when it is open, so as to close the flow channel of the turbine engine 20, and at the same time guide the combustible mixture ejected by the rotary detonation engine 10 to the afterburner 23 for detonation combustion.

[0053] The adjustable tail nozzle 43 is installed at the rear of the inner casing 32. The area between the adjustable tail nozzle 43 and the outer casing 31 constitutes the outer bypass exhaust duct 14 of the rotary detonation engine 10. The area inside the adjustable tail nozzle 43 constitutes the inner bypass exhaust duct 22 of the turbine engine 20. The adjustable tail nozzle 43 is used to adjust the ratio of the outlet area of ​​the outer bypass exhaust duct 14 to the inner bypass exhaust duct 22.

[0054] In this embodiment, when the combined engine is in turbine mode, the inlet regulating valve 41 closes the outer bypass duct, the internal turbine engine 20 operates normally, and the external rotary detonation engine 10 does not operate. When the combined engine is in transition mode, the inlet regulating valve 41 opens, allowing some air to enter the outer bypass duct to supply the rotary detonation engine 10, while the remaining air enters the turbine engine 20 through the inner duct, ensuring the stable operation of the turbine engine 20. The adjustable tail nozzle 43 operates in conjunction with the inlet regulating valve 41 to match the different inflow conditions of the combustion chamber, and the internal turbine engine 20 and the external rotary detonation engine 10 operate simultaneously. When the combined engine is in ramjet rotary detonation mode, the inlet regulating valve 41 closes the outer bypass duct, and the adjustable tail nozzle 43 closes the turbine-driven flow path, the internal turbine engine 20 does not operate, and the external rotary detonation engine 10 operates normally. When the combined engine is in afterburning rotary detonation mode, and the external rotary detonation engine 10 is operating normally, the afterburner flow guide valve 50 opens to form a guide channel, guiding the combustible mixture ejected by the rotary detonation engine 10 to the afterburner 23 of the turbine engine 20 for detonation combustion. This embodiment achieves a smooth transition between different operating states of the combined engine through a mode switching device. Mode switching of the combined engine is achieved through the inlet regulating valve 41 and the adjustable tail nozzle 43, effectively connecting to the upper operating limit of the turbine engine 20, completing power relay, and thus bridging the thrust gap.

[0055] In this embodiment, the combustible mixture ejected from the rotary detonation engine 10 is guided to the afterburner 23 of the turbine engine 20 for detonation combustion by the afterburner flow guide valve 50 when the combined engine is in the afterburner rotary detonation mode. The original cooling device of the afterburner 23 is used for thermal protection to prevent the outer casing 31 from being damaged by high temperature.

[0056] It should be noted that the inner casing 32 is also equipped with a regulating valve actuation mechanism 42 to drive the inlet regulating valve 41 to actuate, thereby achieving the adjustment of the inlet regulating valve 41; the inner casing 32 is also equipped with a nozzle actuation mechanism 44 to drive the adjustable tail nozzle 43 to actuate, thereby achieving the adjustment of the adjustable tail nozzle 43. The regulating valve actuation mechanism 42 and the nozzle actuation mechanism 44 can adopt existing structures.

[0057] Further, see Figures 1-6 The inner casing 32 includes a front section and a rear section. The afterburner flow guide valve 50 includes an adjustable inner wall 51 and an adjustable outer wall 52. One end of the adjustable inner wall 51 is hinged to the front section of the casing, and one end of the adjustable outer wall 52 is hinged to the rear section of the casing. The adjustable inner wall 51 and the adjustable outer wall 52 are used to form a structure connecting the front section and the rear section of the casing when they are closed, and to form a guide flow channel when they are open, so as to close the flow channel of the turbine engine 20 and guide the combustible mixture ejected by the rotary detonation engine 10 to the afterburner 23 for detonation combustion.

[0058] Specifically, the front section of the casing is equipped with an adjustable inner wall actuation mechanism to drive the adjustable inner wall 51 to move, and the rear section of the casing is equipped with an adjustable outer wall actuation mechanism to drive the adjustable outer wall 52 to move. When the afterburner flow guide valve 50 is in the closed state, the adjustable inner wall actuation mechanism and the adjustable outer wall actuation mechanism control the adjustable inner wall 51 and the adjustable outer wall 52 to close respectively, forming a structure connecting the front section and the rear section of the casing; when the afterburner flow guide valve 50 is in the open state, the adjustable inner wall actuation mechanism and the adjustable outer wall actuation mechanism control the adjustable inner wall 51 and the adjustable outer wall 52 to open in different directions respectively, so as to form a guide flow channel. Among them, the adjustable inner wall 51 closes the flow channel of the turbine engine 20, and the adjustable outer wall 52 blocks the outer bypass exhaust channel 14. The guide flow channel guides the combustible mixture ejected by the rotary detonation engine 10 to the afterburner 23 of the turbine engine 20 for detonation combustion. It should be noted that both the adjustable inner wall actuation mechanism and the adjustable outer wall actuation mechanism can use existing structures.

[0059] In this embodiment, without adding extra external structure and volume to the combined engine, an afterburner guide valve 50 is installed on the inner casing 32. This guide valve directs the combustible mixture ejected from the rotating detonation engine 10 to the afterburner 23 of the turbine engine 20 for detonation combustion via a guide channel. The existing cooling device of the afterburner 23 provides thermal protection, enabling the combined engine to reach a preset speed. If the combustible mixture ejected from the rotating detonation engine 10 undergoes detonation combustion in the outer bypass rotating detonation combustion chamber 13 within the outer bypass duct, the outer casing 31 will be damaged due to insufficient cooling once the flight speed exceeds a certain threshold, unless an additional cooling structure is added. However, the inner bypass afterburner 23 itself has a cooling device, and its cooling capacity is superior to that of the outer casing 31. Therefore, this embodiment, by guiding the combustible mixture ejected from the rotating detonation engine 10 to the afterburner 23 of the turbine engine 20 for detonation combustion, effectively prevents damage to the outer casing 31 due to high temperatures.

[0060] Based on the same inventive concept, this embodiment also provides a control method for a high-efficiency thermally protected hybrid thermodynamic cycle combined engine, used to control the aforementioned high-efficiency thermally protected hybrid thermodynamic cycle combined engine, including:

[0061] See Figure 3 When the operating speed of the combined engine is less than or equal to the first speed threshold, the inlet regulating valve 41 is controlled to close the outer bypass duct, the adjustable tail nozzle 43 closes the outer bypass exhaust duct 14, the rotary detonation engine 10 is turned off, the intake airflow enters the inner duct, the turbine engine 20 runs, and the combined engine is in turbine mode.

[0062] Specifically, when the combined engine's operating speed is less than or equal to the first speed threshold, such as when the aircraft is in the takeoff or low-speed flight range, the internal turbine engine 20 operates normally under these flight conditions, while the external rotating detonation engine 10 does not operate. At this time, the regulating valve actuation mechanism 42 and the nozzle actuation mechanism 44 respectively adjust the inlet regulating valve 41 and the adjustable tail nozzle 43 to... Figure 3 In the state where the flow channel of the external rotating detonation engine 10 is closed and the external rotating detonation combustion chamber 13 is not working, all airflow enters the internal turbine engine 20, and the main combustion chamber and afterburner 23 work to consume fuel and generate thrust. At this time, the turbine engine 20 provides the entire power source for the aircraft.

[0063] See Figure 4When the operating speed of the combined engine is between the first speed threshold and the second speed threshold, and the first speed threshold is less than the second speed threshold, the inlet regulating valve 41 is controlled to open the bypass duct, the adjustable tail nozzle 43 opens the bypass exhaust duct 14, the rotating detonation engine 10 and the turbine engine 20 operate simultaneously, and the combined engine is in the transition mode.

[0064] Specific, specific, such as Figure 4 As shown, when the combined engine's operating speed is between the first and second speed thresholds, the internal turbine engine 20 is at its upper operating boundary under these flight conditions, and its performance gradually decreases, but it can still maintain normal flight of the aircraft. The external rotating detonation engine 10 starts to operate, and the rotating detonation engine 10 and the turbine engine 20 operate simultaneously, with the combined engine in a transition mode. At this time, as... Figure 4 As shown, according to the preset linkage mechanism between the inlet regulating valve 41 and the adjustable tail nozzle 43, the regulating valve actuation mechanism 42 controls the inlet regulating valve 41 to gradually open the outer bypass duct. The angle of the inlet regulating valve 41 relative to the radial section of the combined engine gradually decreases, the air intake area of ​​the inner duct decreases, and the airflow entering the turbine intake duct gradually decreases. At this time, the working state of the internal turbine engine 20 gradually decreases. Due to the increase in the air intake area of ​​the outer bypass duct, the airflow entering the detonation ramjet duct 11 gradually increases. Some of the airflow enters the detonation ramjet duct 11, and the outer bypass rotating detonation combustion chamber 13 starts to work. The nozzle actuation mechanism 44 adjusts the adjustable tail nozzle 43 to open the outer bypass exhaust duct 14 and deflect it to a predetermined position to match the working state of the combustion chamber under different incoming flows. At this time, the external rotating detonation engine 10 and the internal turbine engine 20 jointly provide power to the aircraft.

[0065] See Figure 5 When the flight speed is between the second speed threshold and the third speed threshold, and the second speed threshold is less than the third speed threshold, the inlet regulating valve 41 is controlled to close the inner duct, and at the same time the adjustable tail nozzle 43 closes the inner exhaust duct 22 of the turbine engine 20. The rotating detonation engine 10 is running, the turbine engine 20 is shut down, and the combined engine is in the rotating detonation mode.

[0066] Specifically, when the flight speed is between the second and third speed thresholds, i.e., when the aircraft further accelerates to a higher flight Mach number, under the incoming flow conditions in this state, the internal turbine engine 20 can no longer function properly to provide effective thrust, while the external rotating detonation engine 10 functions normally. At this time, the regulating valve actuation mechanism 42 controls the inlet regulating valve 41 to actuate to... Figure 5 Position, and simultaneously the nozzle actuator 44 adjusts the nozzle to the desired position. Figure 5The position, namely the inlet regulating valve 41, completely seals the turbine intake, while the wall of the adjustable tail nozzle 43 completely seals the outlet of the afterburner 23. The internal turbine engine 20 stops working, and all airflow enters the external rotating detonation engine 10. The external rotating detonation combustion chamber 13 works to consume fuel and generate thrust, providing the aircraft with all power sources.

[0067] See Figure 6 When the flight speed is greater than or equal to the third speed threshold, the inlet regulating valve 41 is controlled to close the inner exhaust duct, the adjustable inner wall 51 and adjustable outer wall 52 of the afterburner guide valve 50 open and form a guide flow channel, the rotary detonation engine 10 operates, and the combined engine is in afterburner rotary detonation mode; wherein the adjustable inner wall 51 closes the inner exhaust duct 22 of the turbine engine 20, the adjustable outer wall 52 blocks the outer exhaust duct 14, and the guide flow channel guides the combustible mixture ejected by the rotary detonation engine 10 to the afterburner 23 for detonation combustion;

[0068] Specifically, when the flight speed exceeds the third speed threshold, i.e., when the aircraft accelerates further, in order to facilitate efficient thermal protection of the outer casing 31, the combustible mixture ejected from the rotating detonation engine 10 is introduced into the afterburner 23 to organize detonation combustion. The existing cooling system of the afterburner 23 is used for thermal protection to prevent the outer casing 31 from overheating and being damaged. At this time, the adjustable inner wall actuation mechanism controls the adjustable inner wall 51 to move inward towards the engine, cooperating with the inlet regulating valve 41 to seal the internal turbine engine 20. At the same time, the adjustable outer wall actuation mechanism controls the adjustable outer wall 52 to move outward, forming a guide channel to guide the airflow from the outer bypass rotating detonation combustion chamber 13 into the afterburner 23 to reorganize detonation combustion. Simultaneously, the nozzle actuation mechanism 44 controls the adjustable tail nozzle 43 to move outward, changing the nozzle area ratio in a timely manner, so that the high-temperature and high-pressure airflow generated by the afterburner 23 expands and accelerates through the inner exhaust duct 22 to generate thrust, and the outer bypass exhaust duct 14 stops working.

[0069] Compared to a conventional annular rotating detonation combustor, the combined engine in this embodiment, during afterburner rotating detonation mode, introduces the bypass ramjet airflow into the afterburner 23. This transforms the rotating detonation wave organization channel from annular to cylindrical, creating a localized recirculation zone at the head of the cylindrical combustor. This localized heating of the injected combustible mixture accelerates the evaporation of liquid fuel, forming a more uniform combustible mixture layer, which is beneficial for the stable propagation of the rotating detonation wave. In this mode, all power to the aircraft is provided by the afterburner 23 operating in ramjet detonation mode.

[0070] Furthermore, based on the flight state of the combined engine, when the combined engine is in turbine mode, transition mode, and rotating detonation mode, a preset linkage mechanism between the inlet regulating valve 41 and the adjustable tail nozzle 43 is used to adjust the intake flow ratio between the outer bypass duct and the inner duct, and simultaneously adjust the outlet area ratio between the outer bypass exhaust duct 14 and the inner exhaust duct 22. Specifically, the method for determining the preset linkage mechanism between the inlet regulating valve 41 and the adjustable tail nozzle 43 is as follows:

[0071] Based on the combined engine's dimensional parameters, a finite element analysis model of the combined engine is constructed.

[0072] The finite element analysis model was used to simulate and analyze the total inlet pressure of the outer bypass exhaust duct 14, the total inlet temperature of the outer bypass exhaust duct 14, and the minimum throat area required by the outer bypass exhaust duct 14 under different flight conditions and different combinations of inlet regulating valve 41 angles.

[0073] Based on the environmental back pressure under each flight state and the total inlet pressure of the bypass exhaust duct 14 under the corresponding combination of conditions, the maximum Mach number of the outlet airflow of the bypass exhaust duct 14 under the corresponding combination of conditions is obtained.

[0074] Based on the minimum throat area and the maximum Mach number, the outlet area of ​​the outer bypass exhaust duct 14 under the corresponding combination conditions is obtained by analysis.

[0075] Using the inlet regulating valve 41 angle, the total inlet pressure of the bypass exhaust duct 14, the total inlet temperature of the bypass exhaust duct 14, and the maximum Mach number of the airflow at the outlet of the bypass exhaust duct 14 under each combination condition as inputs, and the outlet area of ​​the bypass exhaust duct 14 under the corresponding combination condition as output, an analysis function for the outlet area of ​​the bypass exhaust duct 14 based on the inlet regulating valve 41 angle is constructed.

[0076] Based on the total inlet pressure of the bypass exhaust duct 14, the total inlet temperature of the bypass exhaust duct 14, the maximum Mach number of the airflow at the outlet of the bypass exhaust duct 14, and the required outlet area of ​​the bypass exhaust duct 14, the angle value of the inlet regulating valve 41 under the analysis state is obtained by using the analysis function.

[0077] Based on the angle value of the inlet regulating valve 41 under the state to be analyzed and the required outlet area of ​​the outer bypass exhaust duct 14, the inlet regulating valve 41 and the adjustable tail nozzle 43 are controlled to operate.

[0078] Furthermore, the minimum throat area required for the outer duct exhaust duct 14 is determined by... Analysis yielded, among which, The outlet area of ​​the outer duct exhaust duct 14 under the corresponding combination conditions. To design the intake coefficient, air density, For intake speed, For the total temperature of the 14 inlet of the outer duct exhaust duct, The radius of the outer casing 31 The radius of the inner casing 32 is... The length of the inlet regulating valve 41 The angle of the inlet regulating valve 41 relative to the radial section of the combined engine. To design the flow coefficient, For the total pressure at the inlet of the 14th duct of the outer bypass exhaust duct, To design specific flow density.

[0079] Furthermore, the maximum Mach number of the outlet airflow of the bypass exhaust duct 14 under the corresponding combination conditions is determined by... Analysis yielded, among which, The maximum Mach number of the airflow at the outlet of the outer bypass exhaust duct 14. To design the specific heat ratio, For the total pressure at the inlet of the 14th duct of the outer bypass exhaust duct, This corresponds to the environmental back pressure during flight.

[0080] Furthermore, the analysis function for the outlet area of ​​the bypass exhaust duct based on the angle of the inlet regulating valve 41 is:

[0081] ,

[0082] in, The outlet area of ​​the outer duct exhaust duct 14 is [missing information]. To design the intake coefficient, air density, For intake speed, For the total temperature of the 14 inlet of the outer duct exhaust duct, The radius of the outer casing 31 The radius of the inner casing 32 is... The length of the inlet regulating valve 41 The angle of the inlet regulating valve 41 relative to the radial section of the combined engine. To design the flow coefficient, For the total pressure at the inlet of the 14th duct of the outer bypass exhaust duct, To design specific flow density, The maximum Mach number of the airflow at the outlet of the outer bypass exhaust duct 14. This refers to the design specific heat ratio. It should be noted that the design intake coefficient, design flow rate coefficient, design specific flow density, and design specific heat ratio are all commonly used empirical coefficients, and can be selected within a certain range.

[0083] In this embodiment, the intake flow ratio of the outer bypass duct and the inner bypass duct is adjusted by the inlet regulating valve 41, and the outlet area ratio of the outer bypass exhaust duct and the inner bypass exhaust duct is adjusted by the adjustable tail nozzle 43 to match the working state of the main combustion chamber and the afterburner of the turbine engine, and at the same time match the working state of the outer bypass rotary detonation combustion chamber. Through the linkage between the adjustable tail nozzle 43 and the inlet regulating valve 41, the intake flow and combustion chamber state of the turbine engine 20 and the rotary detonation engine 10 are brought to a preset state, thereby reducing the fuel consumption of the combined engine and improving the propulsion efficiency of the combined engine.

[0084] Compared with existing turbo-ramjet combined engines, the combined engine of the present invention has a lower lower limit for the external rotating detonation combustion chamber, which can effectively connect with the upper limit of the turbine engine's operation, complete the power relay, and thus cross the thrust gap.

[0085] Compared with existing turbo-ramjet-rocket combined engines, the combined engine of the present invention has fewer power units, achieves the same thrust-to-weight ratio, has relatively lower structural design complexity, simpler structure and control laws, higher system reliability, and greater feasibility for engineering applications.

[0086] Compared with existing turbine-precooled engines, the combined engine of this invention does not require additional consideration of the coupling problem between the precooling unit and the power unit, has relatively low structural design complexity, relatively simple structure and control law, higher system reliability, and greater feasibility for engineering applications.

[0087] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-efficiency thermally protected hybrid thermodynamic cycle combined engine, comprising an outer casing (31) and an inner casing (32), and an outer bypass duct between the outer casing (31) and the inner casing (32), characterized in that, The hybrid thermodynamic cycle combined engine also includes: Rotary detonation engine (10), wherein the rotary detonation engine (10) is disposed within the outer duct; A turbine engine (20) is disposed in the inner casing (32); The mode switching device includes an inlet regulating valve (41), an afterburner flow guide valve (50), and an adjustable tail nozzle (43); The inlet regulating valve (41) is located at the front end of the inner casing (32) and at the inlet of the outer bypass duct, and is used to regulate the air intake flow ratio between the outer bypass duct and the inner casing. The adjustable tail nozzle (43) is installed at the rear of the inner casing (32). The area between the adjustable tail nozzle (43) and the outer casing (31) constitutes the outer bypass exhaust duct (14) of the rotary detonation engine (10). The area inside the adjustable tail nozzle (43) constitutes the inner bypass exhaust duct (22) of the turbine engine (20). The adjustable tail nozzle (43) is used to adjust the ratio of the outlet area of ​​the outer bypass exhaust duct (14) and the inner bypass exhaust duct (22). The afterburner flow guide valve (50) is located on the inner casing (32). An afterburner (23) is provided between the turbine component of the turbine engine (20) and the adjustable tail nozzle (43). The afterburner flow guide valve (50) is used to form a guide channel when it is open, so as to close the flow channel of the turbine engine (20) and guide the combustible mixture ejected by the rotary detonation engine (10) to the afterburner (23) for detonation combustion. The inner casing (32) includes a front section and a rear section. The afterburner flow guide valve (50) includes an adjustable inner wall (51) and an adjustable outer wall (52). One end of the adjustable inner wall (51) is hinged to the front section of the casing, and one end of the adjustable outer wall (52) is hinged to the rear section of the casing. The adjustable inner wall (51) and the adjustable outer wall (52) are used to form a structure connecting the front section and the rear section of the casing when they are closed, and to form a guide flow channel when they are open, so as to close the flow channel of the turbine engine (20) and guide the combustible mixture ejected by the rotary detonation engine (10) to the afterburner (23) for detonation combustion.

2. The hybrid thermodynamic cycle combined engine with high-efficiency thermal protection according to claim 1, characterized in that, The rotary detonation engine (10) includes a detonation injection structure (12) disposed in the outer duct; the area from the inlet of the outer duct to the front end of the detonation injection structure (12) is a detonation ramming duct (11); the rear end of the detonation injection structure (12) is an outer duct rotary detonation combustion chamber (13), which is connected to the outer duct exhaust duct (14).

3. A control method for a high-efficiency thermally protected hybrid thermodynamic cycle combined engine, used to control the high-efficiency thermally protected hybrid thermodynamic cycle combined engine as described in any one of claims 1-2, characterized in that, include: When the operating speed of the hybrid thermodynamic cycle combined engine is less than or equal to the first speed threshold, the inlet regulating valve (41) is controlled to close the outer bypass duct, the adjustable tail nozzle (43) closes the outer bypass exhaust duct (14), the rotary detonation engine (10) is turned off, the intake air flow enters the inner duct, the turbine engine (20) runs, and the hybrid thermodynamic cycle combined engine is in turbine mode. When the operating speed of the hybrid thermodynamic cycle combined engine is between the first speed threshold and the second speed threshold, and the first speed threshold is less than the second speed threshold, the inlet regulating valve (41) is controlled to open the bypass duct, the adjustable tail nozzle (43) opens the bypass exhaust duct (14), the rotating detonation engine (10) and the turbine engine (20) operate simultaneously, and the hybrid thermodynamic cycle combined engine is in the transition mode; When the flight speed is between the second speed threshold and the third speed threshold, and the second speed threshold is less than the third speed threshold, the inlet regulating valve (41) is controlled to close the inner channel, and at the same time the adjustable tail nozzle (43) closes the inner exhaust channel (22) of the turbine engine (20), the rotating detonation engine (10) is running, the turbine engine (20) is shut down, and the hybrid thermodynamic cycle combined engine is in the rotating detonation mode; When the flight speed is greater than or equal to the third speed threshold, the inlet regulating valve (41) is controlled to close the inner channel, the adjustable inner wall (51) and adjustable outer wall (52) of the afterburner guide valve (50) are opened to form a guide channel, the rotary detonation engine (10) is running, and the hybrid thermodynamic cycle combined engine is in the afterburner rotary detonation mode; wherein the adjustable inner wall (51) closes the inner exhaust channel (22) of the turbine engine (20), the adjustable outer wall (52) blocks the outer exhaust channel (14), and the guide channel guides the combustible mixture ejected by the rotary detonation engine (10) to the afterburner (23) for detonation combustion; According to the flight state of the hybrid thermocycle combined engine, when the hybrid thermocycle combined engine is in turbine mode, transition mode and rotating detonation mode, the preset linkage action mechanism of the inlet regulating valve (41) and the adjustable tail nozzle (43) is adopted to adjust the intake flow ratio of the outer bypass duct and the inner duct, and at the same time, the outlet area ratio of the outer bypass exhaust duct (14) and the inner exhaust duct (22) is adjusted in linkage.

4. The hybrid thermodynamic cycle combined engine control method according to claim 3, characterized in that, The method for determining the preset linkage mechanism between the inlet regulating valve (41) and the adjustable tail nozzle (43) is as follows: Based on the dimensional parameters of the hybrid thermodynamic cycle combined engine, a finite element analysis model of the hybrid thermodynamic cycle combined engine is constructed. The finite element analysis model was used for simulation analysis to obtain the total inlet pressure of the bypass exhaust duct (14), the total inlet temperature of the bypass exhaust duct (14), and the minimum throat area required by the bypass exhaust duct (14) under different flight states and different combinations of inlet regulating valve (41) angles. Based on the environmental back pressure under each flight condition and the total inlet pressure of the bypass exhaust duct (14) under the corresponding combination conditions, the maximum Mach number of the outlet airflow of the bypass exhaust duct (14) under the corresponding combination conditions is obtained. Based on the minimum throat area and the maximum Mach number, the outlet area of ​​the outer bypass exhaust duct (14) under the corresponding combination conditions is obtained by analysis; Using the angle of the inlet regulating valve (41), the total pressure at the inlet of the bypass exhaust duct (14), the total temperature at the inlet of the bypass exhaust duct (14), and the maximum Mach number of the airflow at the outlet of the bypass exhaust duct (14) under each combination condition as inputs, and the outlet area of ​​the bypass exhaust duct (14) under the corresponding combination condition as output, an analysis function for the outlet area of ​​the bypass exhaust duct (14) based on the angle of the inlet regulating valve (41) is constructed. Based on the total inlet pressure, total inlet temperature, and maximum Mach number of the outlet airflow of the bypass exhaust duct (14) of the hybrid thermodynamic cycle combined engine under the state to be analyzed, and the required outlet area of ​​the bypass exhaust duct (14), the angle value of the inlet regulating valve (41) under the state to be analyzed is obtained by using the analysis function. Based on the angle value of the inlet regulating valve (41) under the state to be analyzed and the required outlet area of ​​the outer bypass exhaust duct (14), the inlet regulating valve (41) and the adjustable tail nozzle are controlled to operate.

5. The hybrid thermodynamic cycle combined engine control method according to claim 4, characterized in that, The minimum throat area required for the outer duct exhaust duct (14) is obtained through The analysis yielded the following results: The outlet area of ​​the outer duct exhaust duct (14) under the corresponding combination conditions, To design the intake coefficient, air density, For intake speed, The total inlet temperature of the duct exhaust duct (14) is... The radius of the outer casing (31) is... The radius of the inner casing (32) is... The length of the inlet regulating valve (41) The angle of the inlet regulating valve (41) relative to the radial section of the hybrid thermodynamic cycle combined engine. To design the flow coefficient, For the total inlet pressure of the outer duct exhaust duct (14), To design specific flow density.

6. The control method for a hybrid thermodynamic cycle combined engine according to claim 5, characterized in that, The maximum Mach number of the outlet airflow of the outer bypass exhaust duct (14) under the corresponding combination conditions is passed through The analysis yielded the following results: The maximum Mach number of the airflow at the outlet of the outer bypass exhaust duct (14) is... To design the specific heat ratio, For the total inlet pressure of the outer duct exhaust duct (14), This corresponds to the environmental back pressure during flight.

7. The hybrid thermodynamic cycle combined engine control method according to claim 6, characterized in that, The outlet area analysis function of the outer bypass exhaust duct (14) based on the angle of the inlet regulating valve (41) is: in, The outlet area of ​​the outer duct exhaust duct (14) is given. To design the intake coefficient, air density, For intake speed, The total inlet temperature of the duct exhaust duct (14) is... The radius of the outer casing (31) is... The radius of the inner casing (32) is... The length of the inlet regulating valve (41) The angle of the inlet regulating valve (41) relative to the radial section of the hybrid thermodynamic cycle combined engine. To design the flow coefficient, For the total inlet pressure of the outer duct exhaust duct (14), To design specific flow density, The maximum Mach number of the airflow at the outlet of the outer bypass exhaust duct (14) is... To design the specific heat ratio.

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