Variable cycle engine core engine driving fan anti-surge system, method and device

Abstract

The invention relates to the technical field of aero-engines, and discloses a variable cycle engine core engine driving fan anti-surge system, method and device. The anti-surge system comprises an engine electronic control system used for controlling the working state of a throttling device, the working state of an opening-degree-adjustable pre-rotation valve and the working state of an opening-degree-adjustable deflation valve according to aircraft performance parameters; the throttling device is used for controlling the flow of the air inlet main airflow entering the core engine driving fan; the opening-degree-adjustable pre-swirling valve is used for controlling the flow of the anti-surge deflation airflow generating the pre-swirling airflow; the pre-swirling airflow is converged into the air inlet main airflow; the anti-surge deflation airflow is discharged from the middle stage of the high-pressure compressor; and the opening-adjustable deflation valve is used for controlling the flow of the anti-surge deflation airflow discharged into the outer culvert channel. According to the scheme, on the premise that the efficiency is guaranteed, the scheme is simple, convenient and flexible, and the cost is low, airflow separation on the blade backs is eliminated, and the surge phenomenon is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of aeroengines, and particularly to an anti-surge system, method and device for a core engine-driven fan of a variable cycle engine. Background Art

[0002] A variable cycle engine can switch between two turbofan / turbojet cycle modes to adapt to the flight of an aircraft at different speeds. This requires the high-pressure compressor of the variable cycle engine to be able to adapt to a large range of air flow rate changes, posing a challenge to the design of the anti-surge system of the high-pressure compressor.

[0003] During the process of the flight speed of the aircraft continuously decreasing from supersonic speed to subsonic speed, the throttle device of the variable cycle engine closes the mode conversion valve, and closes the front bypass ejector and the rear bypass ejector, so that the bypass ratio of the engine continuously increases, the flow rate in front of the core engine-driven fan continuously decreases, and the core engine rotor speed approximately remains unchanged. To prevent surge from occurring during this process, in the related art, a method of adjustable guide vanes plus anti-surge bleed is adopted to achieve engine anti-surge. However, direct bleeding will reduce the efficiency of the high-pressure compressor, and the adjustable guide vane has a complex structure, high cost and narrow application range. Summary of the Invention

[0004] In view of this, the present invention provides an anti-surge system, method and device for a core engine-driven fan of a variable cycle engine to solve the problems of low efficiency and narrow application range of the anti-surge scheme in the related art.

[0005] In a first aspect, the present invention provides an anti-surge system for a core engine-driven fan of a variable cycle engine, and the anti-surge system includes:

[0006] An engine electronic control system, configured to control the working state of a throttle device, the working state of an adjustable-opening pre-whirl valve, and the working state of an adjustable-opening bleed valve according to aircraft performance parameters;

[0007] The throttle device is electrically connected to the engine electronic control system and is configured to control the flow rate of the main intake air flow entering the core engine-driven fan according to the instruction of the engine electronic control system;

[0008] The adjustable-opening pre-whirl valve is electrically connected to the engine electronic control system and is configured to control the flow rate of the anti-surge bleed air flow for generating a pre-whirl air flow according to the instruction of the engine electronic control system; the pre-whirl air flow converges into the main intake air flow; the anti-surge bleed air flow is discharged from an intermediate stage of the high-pressure compressor;

[0009] The adjustable-opening bleed valve is electrically connected to the engine electronic control system and is configured to control the flow rate of the anti-surge bleed air flow discharged into the outer bypass passage according to the instruction of the engine electronic control system.

[0010] In an alternative embodiment, the anti-surge system further includes a pre-whirl air flow generator;

[0011] The pre-whirl air flow generator is configured to generate a pre-whirl air flow based on the anti-surge bleed air flow discharged from the adjustable-opening pre-whirl valve and merge the pre-whirl air flow into the main intake air flow.

[0012] In an alternative embodiment, the anti-surge system further includes an air supply chamber;

[0013] The air supply chamber is configured to store the anti-surge bleed air flow discharged from the intermediate stage of the high-pressure compressor and discharge the anti-surge bleed air flow into the pre-whirl air flow generator through the adjustable-opening pre-whirl valve; or discharge the anti-surge bleed air flow into the outer bypass passage through the adjustable-opening bleed valve.

[0014] In a second aspect, the present invention provides a method for preventing surge in a variable cycle engine core-driven fan, which is applied to an engine electronic control system in a variable cycle engine core-driven fan anti-surge system. The method includes:

[0015] Obtain aircraft performance parameters;

[0016] According to the aircraft performance parameters, control the working state of the throttle device to enable the throttle device to control the flow rate of the main intake air flow entering the core-driven fan;

[0017] According to the aircraft performance parameters and the working state of the throttle device, control the working state of the adjustable-opening pre-whirl valve to enable the adjustable-opening pre-whirl valve to adjust the flow rate of the anti-surge bleed air flow used to generate the pre-whirl air flow; the pre-whirl air flow merges into the main intake air flow; the anti-surge bleed air flow is discharged from the intermediate stage of the high-pressure compressor;

[0018] According to the anti-surge result of the adjustable-opening pre-whirl valve, control the working state of the adjustable-opening bleed valve to enable the adjustable-opening bleed valve to control the flow rate of the anti-surge bleed air flow discharged into the outer bypass passage.

[0019] In an alternative embodiment, the controlling the working state of the adjustable-opening pre-whirl valve according to the aircraft performance parameters and the working state of the throttle device includes:

[0020] Obtain the performance parameters of the merged air flow after the main intake air flow and the pre-whirl air flow are merged;

[0021] Based on the performance parameters of the merged air flow, calculate the positive angle of attack of the merged air flow entering the high-pressure compressor;

[0022] Compare the positive angle of attack of the intake air with a preset positive angle of attack of the intake air to adjust the opening degree of the adjustable-opening pre-whirl valve;

[0023] Controlling the operating state of the adjustable-opening bleed valve according to the anti-surge result of the adjustable-opening prewhirl valve includes:

[0024] Adjusting the opening of the adjustable-opening bleed valve based on the anti-surge result of the adjustable-opening prewhirl valve.

[0025] In an optional implementation manner, adjusting the opening of the adjustable-opening prewhirl valve includes:

[0026] When the inlet positive angle of attack is greater than the preset inlet positive angle of attack, increasing the opening of the adjustable-opening prewhirl valve;

[0027] Controlling the opening of the adjustable-opening bleed valve includes:

[0028] When the anti-surge result of the adjustable-opening prewhirl valve does not meet the preset conditions, increasing the opening of the adjustable-opening bleed valve.

[0029] In a third aspect, the present invention provides a variable cycle engine core engine-driven fan anti-surge device, which is applied to the engine electronic control system in the variable cycle engine core engine-driven fan anti-surge system. The device includes:

[0030] An acquisition module for acquiring aircraft performance parameters;

[0031] A throttle adjustment module for controlling the operating state of the throttle device according to the aircraft performance parameters, so that the throttle device controls the flow rate of the main intake air flow entering the core engine-driven fan;

[0032] A prewhirl adjustment module for controlling the operating state of the adjustable-opening prewhirl valve according to the aircraft performance parameters and the operating state of the throttle device, so that the adjustable-opening prewhirl valve adjusts the flow rate of the anti-surge bleed air flow used to generate the prewhirl air flow; the prewhirl air flow converges into the main intake air flow; the anti-surge bleed air flow is discharged from the intermediate stage of the high-pressure compressor;

[0033] A bleed adjustment module for controlling the operating state of the adjustable-opening bleed valve according to the anti-surge result of the adjustable-opening prewhirl valve, so that the adjustable-opening bleed valve controls the flow rate of the anti-surge bleed air flow discharged into the bypass duct.

[0034] In a fourth aspect, the present invention provides a computer device, including: a memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to execute the variable cycle engine core engine-driven fan anti-surge method according to the second aspect or any corresponding implementation manner thereof.

[0035] Fifth aspect, the present invention provides a computer-readable storage medium, on which computer instructions are stored, and the computer instructions are used to cause a computer to execute the anti-surge method for the core engine-driven fan of the variable cycle engine according to the second aspect or any corresponding embodiment thereof.

[0036] Sixth aspect, the present invention provides a computer program product, including computer instructions, and the computer instructions are used to cause a computer to execute the anti-surge method for the core engine-driven fan of the variable cycle engine according to the second aspect or any corresponding embodiment thereof.

[0037] The technical solution provided by the present invention may include the following beneficial effects:

[0038] In the anti-surge system for the core engine-driven fan of the variable cycle engine provided by the present invention, the engine electronic control system can control the working state of the throttle device, the working state of the adjustable-opening bleed valve, and the working state of the adjustable-opening pre-whirl valve according to the aircraft performance parameters, and further control the flow rate of the main intake air flow entering the core engine-driven fan, the flow rate of the anti-surge bleed air flow used to generate the pre-whirl air flow, and the flow rate of the anti-surge bleed air flow discharged into the bypass duct, so as to adjust the flow rate and direction of the combined air flow of the main intake air flow and the pre-whirl air flow, and further change the pre-whirl amount at the inlet of the high-pressure compressor, so that the angle of attack of the air flow at the inlet of the first-stage rotor blade of the high-pressure compressor is restored to a value close to the designed state, without the need for adjustable guide vanes with complex structures and high costs, eliminating the air flow separation on the blade back and avoiding the occurrence of surge phenomena on the premise of ensuring the compressor efficiency, simplicity and flexibility of the solution, and low cost. Description of the Drawings

[0039] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0040] Figure 1 Shows a schematic structural diagram of a variable cycle engine in the related art;

[0041] Figure 2 Is a schematic structural diagram of an anti-surge system for a core engine-driven fan of a variable cycle engine according to an embodiment of the present invention;

[0042] Figure 3 Is a schematic flowchart of an anti-surge method for a core engine-driven fan of a variable cycle engine according to an embodiment of the present invention;

[0043] Figure 4It is a schematic flowchart of a method for preventing surge of a core engine-driven fan of a variable cycle engine according to an embodiment of the present invention;

[0044] Figure 5 It is a structural block diagram of a device for preventing surge of a core engine-driven fan of a variable cycle engine according to an embodiment of the present invention;

[0045] Figure 6 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. Specific embodiments

[0046] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0047] Figure 1 It shows a schematic structural diagram of a variable cycle engine in the related art. The rotor system of the variable cycle engine includes two parts: a high-pressure rotor and a low-pressure rotor. The low-pressure rotor includes a first-stage fan and a low-pressure turbine, which are mechanically and rigidly connected; the high-pressure rotor includes a core engine-driven fan, a high-pressure compressor, and a high-pressure turbine, which are mechanically and rigidly connected. The function of the high-pressure compressor is to increase the pressure of the air entering the variable cycle engine and supply the compressed air required when the variable cycle engine operates. Surge is a low-frequency and high-amplitude oscillation phenomenon that occurs along the axis direction of the high-pressure compressor, and it is a difficult problem faced by multi-stage variable cycle engines. When the variable cycle engine operates in a non-design state, the mismatch in the flow capacity between the front-stage and rear-stage booster stages of the multi-stage high-pressure compressor will cause surge. Specifically, when operating at a speed deviating from the design speed, the axial velocity and the tip speed of the front and rear stages decrease disproportionality. The axial velocity of the front several stages decreases faster than the tip speed, resulting in an excessive positive angle of attack of the air flow and entering an unstable state. The air separates at the trailing edge of the blade and may spread to the entire cascade passage. The axial velocity of the rear several stages decreases slower than the tip speed, resulting in an excessive negative angle of attack of the air flow and entering a blocked state. When surge occurs, the working blades cannot overcome the higher back pressure behind, resulting in the inability of the air to flow backward normally in the high-pressure compressor. The flow rate drops sharply and then rises, the total pressure and flow rate at the inlet of the high-pressure compressor fluctuate greatly, the speed is unstable, and sometimes a low-pitched noise or a popping sound may be emitted. If not dealt with in time, it may cause the engine to stall, or damage the blades due to severe vibration and increase the exhaust temperature.

[0048] A variable cycle engine can switch between two turbofan / turbojet cycle modes. To adapt to flights at different speeds, the high-pressure compressor of a variable cycle engine needs to adapt to a large range of air flow rate changes, which poses challenges to the design of the anti-surge system for the high-pressure compressor. During the process of the aircraft's flight speed continuously decreasing from supersonic to subsonic, the throttle device of the variable cycle engine closes the mode conversion valve and reduces the front bypass ejector and the rear bypass ejector, causing the engine bypass ratio to continuously increase and the flow rate in front of the core engine-driven fan to continuously decrease, while the rotational speed of the core engine rotor remains approximately unchanged. To prevent surge from occurring during this process, in related technologies, a method of adjustable guide vanes plus anti-surge bleed is adopted to achieve engine anti-surge. However, direct bleeding will reduce the efficiency of the high-pressure compressor, and the adjustable guide vane structure is complex, with high costs and a narrow application range.

[0049] In this embodiment, an anti-surge system for a core engine-driven fan of a variable cycle engine is provided. Figure 2 It is a schematic structural diagram of an anti-surge system for a core engine-driven fan of a variable cycle engine according to an embodiment of the present invention, as Figure 2 shown. This anti-surge system includes an engine electronic control system ( Figure 2 not shown in the figure), a throttle device, an adjustable-opening pre-whirl valve, and an adjustable-opening bleed valve.

[0050] The engine electronic control system is used to control the working states of the throttle device, the adjustable-opening pre-whirl valve, and the adjustable-opening bleed valve according to the aircraft performance parameters.

[0051] The throttle device is electrically connected to the engine electronic control system and is used to control the flow rate of the main intake air flow entering the core engine-driven fan according to the instruction of the engine electronic control system.

[0052] The adjustable-opening pre-whirl valve is electrically connected to the engine electronic control system and is used to control the flow rate of the anti-surge bleed air flow for generating pre-whirl air flow according to the instruction of the engine electronic control system; this pre-whirl air flow merges into the main intake air flow; this anti-surge bleed air flow is discharged from the intermediate stage of the high-pressure compressor.

[0053] The adjustable-opening bleed valve is electrically connected to the engine electronic control system and is used to control the flow rate of the anti-surge bleed air flow discharged into the bypass duct according to the instruction of the engine electronic control system.

[0054] In an actual application scenario, sensors can be set in the variable cycle engine of the aircraft, such as an intake air temperature sensor, an intake air pressure sensor, an air flow rate sensor, etc. These sensors are electrically connected to the engine electronic control system and are used to send the collected corresponding aircraft performance parameters to the engine electronic control system, and the engine electronic control system can then control the working process of the variable cycle engine according to the received aircraft performance parameters.

[0055] In the present application, the engine electronic control system can control the working states of the throttle device, the variable-opening bleed valve, and the variable-opening pre-whirl valve according to the aircraft performance parameters transmitted by sensors, such as the throttle device valve opening, engine speed, temperature of the main intake air stream, flight altitude, and flight speed. Specifically, the main intake air stream is inhaled from the outside by the throttle device. After passing through the first-stage fan, a part of the main intake air stream is discharged through the bypass duct, and a part enters the core engine to drive the fan through the core duct. When there is more air flow in the bypass duct, the variable cycle engine operates in the turbofan cycle mode, at which time the fuel consumption rate is low and it is suitable for subsonic long-distance cruising; when there is less air in the bypass duct, the variable cycle engine operates in the turbojet cycle mode, at which time the thrust is greater and it is suitable for high-altitude and high-speed flight. By adjusting the throttle device, the air flow rate in front of the core engine driving the fan can be adjusted. The throttle device is a set of combined valves, including a mode conversion valve, a front bypass ejector, and a rear bypass ejector.

[0056] The anti-surge bleed air flow is a part of the air discharged for anti-surge after being compressed by the first few stages (referred to as the front part) in front of the high-pressure compressor. The throttle device can adjust the flow rate of the main intake air stream entering the core engine driving the fan by adjusting the angle, opening degree, etc. of the actuator. The variable-opening bleed valve can be a device including an electronically controlled valve, which is arranged on the path through which the anti-surge bleed air flow passes and can adjust the flow rate of the anti-surge bleed air flow discharged by adjusting the opening degree of the electronically controlled valve.

[0057] During the flight of the aircraft, when the variable cycle engine changes from the turbojet cycle mode to the turbofan cycle mode, the engine electronic control system sends a flow control command to the throttle device to control the throttle device to adjust the flow rate of the main intake air stream entering the core engine driving the fan, so as to reduce the main air stream flow rate of the core engine driving the fan.

[0058] The component of the absolute velocity of the first-stage rotor blade of a high-pressure compressor at the inlet in the tangential direction is called pre-whirl. The function of pre-whirl is to prevent the airflow from separating at the blade back and to prevent the high-pressure compressor from surging. A part of the anti-surge bleed airflow discharged from the intermediate stage of the high-pressure compressor passes through an adjustable-opening bleed valve and is discharged into the outer bypass duct, and a part flows out from the adjustable-opening pre-whirl valve, is converted into pre-whirl airflow, and then merges into the main intake airflow. After the pre-whirl airflow and the main intake airflow merge, their directions will affect each other and their flows will be added to obtain the merged airflow. That is to say, by controlling the working state of the throttle device, the working state of the adjustable-opening bleed valve, and the working state of the adjustable-opening pre-whirl valve, the flow and direction of the merged airflow formed after the pre-whirl airflow and the main intake airflow merge can be changed, thereby changing the inlet pre-whirl amount of the high-pressure compressor, making the angle of attack of the inlet airflow of the first-stage rotor blade of the high-pressure compressor return to a value close to the designed state, eliminating the airflow separation on the blade back, and avoiding the occurrence of the surging phenomenon. In an alternative embodiment, the anti-surge system further includes a pre-whirl airflow generator. The pre-whirl airflow generator is used to generate pre-whirl airflow according to the anti-surge bleed airflow discharged from the adjustable-opening pre-whirl valve and merge the pre-whirl airflow into the main intake airflow. That is to say, the anti-surge bleed airflow flowing out from the adjustable-opening pre-whirl valve is converted into pre-whirl airflow by the pre-whirl airflow generator and then merges into the main intake airflow.

[0059] In an alternative embodiment, the anti-surge system further includes a gas supply chamber. The gas supply chamber is used to store the anti-surge bleed airflow discharged from the intermediate stage of the high-pressure compressor and discharge the anti-surge bleed airflow into the pre-whirl airflow generator through the adjustable-opening pre-whirl valve; or discharge the anti-surge bleed airflow into the outer bypass duct through the adjustable-opening bleed valve. That is to say, the anti-surge bleed airflow flowing out from the intermediate stage of the high-pressure compressor enters the gas supply chamber for storage. A part of the anti-surge bleed airflow stored in the gas supply chamber is discharged into the outer bypass duct through the adjustable-opening bleed valve, and a part is discharged into the pre-whirl airflow generator through the adjustable-opening pre-whirl valve.

[0060] In the anti-surge system of the core engine-driven fan of the variable cycle engine provided in this embodiment, the engine electronic control system can control the working state of the throttle device, the working state of the adjustable-opening bleed valve, and the working state of the adjustable-opening pre-whirl valve according to the aircraft performance parameters, and then control the flow of the main intake airflow entering the core engine-driven fan, the flow of the anti-surge bleed airflow used to generate pre-whirl airflow, and the flow of the anti-surge bleed airflow discharged into the outer bypass duct, so as to adjust the flow and direction of the merged airflow of the main intake airflow and the pre-whirl airflow, and then change the inlet pre-whirl amount of the high-pressure compressor, making the angle of attack of the inlet airflow of the first-stage rotor blade of the high-pressure compressor return to a value close to the designed state, eliminating the airflow separation on the blade back without the need for adjustable guide vanes with complex structures and high costs, and avoiding the occurrence of the surging phenomenon on the premise of ensuring the compressor efficiency, with a simple and flexible solution and low cost.

[0061] According to an embodiment of the present invention, there is provided an embodiment of a method for preventing surge in a core engine-driven fan of a variable cycle engine. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0062] In this embodiment, a method for preventing surge in a core engine-driven fan of a variable cycle engine is provided, which can be used for Figure 2 the engine electronic control system in the embodiment, Figure 3 is a flowchart of a method for preventing surge in a core engine-driven fan of a variable cycle engine according to an embodiment of the present invention, as Figure 3 shown, the process includes the following steps:

[0063] Step S301, obtain aircraft performance parameters.

[0064] The engine electronic control system obtains aircraft performance parameters through various sensors arranged in the variable cycle engine or by means of communication with corresponding components, such as the throttle valve opening, engine speed, temperature of the main intake air flow, flight altitude, flight speed, ambient temperature, etc.

[0065] Step S302, according to the aircraft performance parameters, control the working state of the throttle device to enable the throttle device to control the flow rate of the main intake air flow entering the core engine-driven fan.

[0066] Based on the aircraft performance parameters, send a control instruction to the throttle device to control the working state of the throttle device, and then adjust the working states of the mode conversion valve, front bypass ejector, rear bypass ejector, variable intake duct, and variable area tail nozzle in the throttle device, so that the mode conversion valve, front bypass ejector, rear bypass ejector, variable intake duct, and variable area tail nozzle act together to control the flow rate of the main intake air flow entering the core engine-driven fan.

[0067] Step S303, according to the aircraft performance parameters and the working state of the throttle device, control the working state of the adjustable opening pre-whirl valve to enable the adjustable opening pre-whirl valve to adjust the flow rate of the anti-surge bleed air flow used to generate the pre-whirl air flow.

[0068] The pre-whirl air flow merges into the main intake air flow; the anti-surge bleed air flow is discharged from the intermediate stage of the high-pressure compressor. A corresponding relationship is established in advance between the working state of the adjustable-opening pre-whirl valve, the valve opening of the throttling device, the engine speed, the temperature of the main intake air flow, the flight altitude, and the flight speed. For example, relevant experiments are carried out in advance, and the corresponding relationship between the working state of the adjustable-opening pre-whirl valve, the valve opening of the throttling device, the engine speed, the temperature of the main intake air flow, the flight altitude, and the flight speed is calculated through the experimental data. Then, in the actual application scenario, according to the valve opening of the throttling device, the engine speed, the temperature of the main intake air flow, the flight altitude, and the flight speed, the working state of the adjustable-opening pre-whirl valve can be controlled to adjust the flow rate of the anti-surge bleed air flow used to generate the pre-whirl air flow.

[0069] Step S304, according to the anti-surge result of the adjustable-opening pre-whirl valve, control the working state of the adjustable-opening bleed valve to enable the adjustable-opening bleed valve to control the flow rate of the anti-surge bleed air flow discharged into the bypass duct.

[0070] The anti-surge result can be monitored by measuring the high-pressure compressor speed, the pressure and temperature in the air supply chamber, the speed (flow rate), pressure and temperature of the main intake air flow, the speed (flow rate), pressure and temperature of the pre-whirl air flow, the dynamic stress of the high-pressure compressor blades, vibration monitoring, and acoustic monitoring, and combining with the existing compressor performance test data. Specifically, according to the high-pressure compressor speed, gas speed (flow rate), temperature, and pressure data, and combining with the existing performance data, it can be determined whether the current working state of the high-pressure compressor is close to the surge boundary. Further, through the pressure signal fluctuation, the measurement result of the dynamic stress of the high-pressure compressor blades, and the engine vibration and acoustic monitoring analysis, it can be determined whether the high-pressure compressor is close to the stall and surge boundaries. The adjustment of the adjustable-opening bleed valve is related to the working state of the throttling device and the working state of the adjustable-opening pre-whirl valve. Specifically, when the flow rate of the main intake air flow is large, the adjustable-opening pre-whirl valve can independently complete the anti-surge function, and the adjustable-opening bleed valve can be closed; when the flow rate of the main intake air flow is small, the engine will still surge only relying on the adjustable-opening pre-whirl valve, that is, the anti-surge result of the adjustable-opening pre-whirl valve does not reach the expectation. At this time, the adjustable-opening bleed valve needs to be opened for bleeding to avoid surging.

[0071] In the engine anti-surge method provided in this embodiment, the engine electronic control system can control the working state of the throttle device, the working state of the variable-opening bleed valve, and the working state of the variable-opening pre-whirl valve according to the aircraft performance parameters, and then control the flow rate of the main intake air flow entering the core engine-driven fan, the flow rate of the anti-surge bleed air flow used to generate the pre-whirl air flow, and the flow rate of the anti-surge bleed air flow discharged into the bypass duct, so as to adjust the flow rate and direction of the combined air flow of the main intake air flow and the pre-whirl air flow, and then change the inlet pre-whirl amount of the high-pressure compressor, so that the angle of attack of the air flow at the inlet of the first-stage rotor blades of the high-pressure compressor is restored to a value close to the design state, without the need for adjustable guide vanes with complex structures and high costs, eliminating the air flow separation on the blade back on the premise of ensuring the compressor efficiency, simple and flexible solution, and low cost, and avoiding the occurrence of surge phenomenon.

[0072] In this embodiment, a method for preventing surge of a core engine-driven fan of a variable cycle engine is provided, which can be used for Figure 2 the engine electronic control system in the embodiment, Figure 4 is a flow chart of the method for preventing surge of a core engine-driven fan of a variable cycle engine according to an embodiment of the present invention, as Figure 4 shown, the process includes the following steps:

[0073] Step S401, obtain aircraft performance parameters.

[0074] For details, please refer to Figure 3 step S301 of the embodiment shown, which will not be elaborated here.

[0075] Step S402, according to the aircraft performance parameters, control the working state of the throttle device, so that the throttle device controls the flow rate of the main intake air flow entering the core engine-driven fan.

[0076] For details, please refer to Figure 3 step S302 of the embodiment shown, which will not be elaborated here.

[0077] Step S403, according to the aircraft performance parameters and the working state of the throttle device, control the working state of the variable-opening pre-whirl valve, so that the variable-opening pre-whirl valve adjusts the flow rate of the anti-surge bleed air flow used to generate the pre-whirl air flow.

[0078] The pre-whirl air flow merges into the main intake air flow; the anti-surge bleed air flow is discharged from the intermediate stage of the high-pressure compressor.

[0079] Specifically, the above step S403 includes:

[0080] Step S4031, obtain the performance parameters of the combined air flow after the main intake air flow and the pre-whirl air flow merge.

[0081] Optionally, sensors for measuring the air flow rate, temperature, and pressure are provided at the inlet of the first-stage rotor blades of the high-pressure compressor to measure the air flow rate, temperature, and pressure at the inlet. Combining the existing experimental data and the principles of mathematics and physics, the air flow direction and air flow rate of the confluent air flow are indirectly estimated to obtain the performance parameters of the confluent air flow.

[0082] Step S4032: Calculate the inlet positive incidence angle of the confluent air flow entering the high-pressure compressor based on the performance parameters of the confluent air flow.

[0083] Based on the air flow direction and air flow rate of the confluent air flow, and combining the existing experimental data, indirectly estimate the inlet positive incidence angle of the confluent air flow entering the high-pressure compressor.

[0084] Step S4033: Compare the inlet positive incidence angle with a preset inlet positive incidence angle to adjust the opening degree of the adjustable-opening prewhirl valve.

[0085] The preset inlet positive incidence angle is the inlet positive incidence angle of the confluent air flow entering the core engine-driven fan corresponding to the engine operating state obtained in advance. When the inlet positive incidence angle is greater than the preset inlet positive incidence angle, increase the opening degree of the adjustable-opening prewhirl valve until the inlet positive incidence angle of the confluent air flow entering the high-pressure compressor is equal to the preset inlet positive incidence angle. Alternatively, a closed-loop control can also be established in the engine electronic control system between the opening degree of the adjustable-opening prewhirl valve and the inlet positive incidence angle of the confluent air flow entering the high-pressure compressor, and the preset inlet positive incidence angle is set as the target value of the closed-loop control to automatically execute the control process until the inlet positive incidence angle is equal to the preset inlet positive incidence angle.

[0086] Step S404: Control the operating state of the adjustable-opening bleed valve according to the anti-surge result of the adjustable-opening prewhirl valve, so that the adjustable-opening bleed valve controls the flow rate of the anti-surge bleed air flow discharged into the bypass duct.

[0087] Specifically, based on the anti-surge result of the adjustable-opening prewhirl valve, adjust the opening degree of the adjustable-opening bleed valve. When the anti-surge result of the adjustable-opening prewhirl valve does not meet the preset conditions, increase the opening degree of the adjustable-opening bleed valve so that the adjustable-opening bleed valve discharges the anti-surge bleed air flow into the bypass duct.

[0088] Optionally, a closed-loop control is established between the opening degrees of the adjustable-opening bleed valve and the adjustable-opening prewhirl valve and the confluent air flow entering the core engine-driven fan to obtain the optimal opening degrees of the adjustable-opening bleed valve and the adjustable-opening prewhirl valve corresponding to each operating state of the engine, so that in most engine operating states, the angle of attack of the air flow at the inlet of the core engine-driven fan blades can be restored to a value close to the design state.

[0089] In this embodiment, a surge prevention device for a variable cycle engine core driven fan is further provided. This device is used to implement the above-mentioned embodiments and preferred implementation manners, and those that have been described will not be repeated. As used hereinafter, the term "module" can be a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation in hardware, or a combination of software and hardware is also possible and contemplated.

[0090] This embodiment provides a surge prevention device for a variable cycle engine core driven fan, which is applied to the engine electronic control system in the surge prevention system of the variable cycle engine core driven fan. As Figure 5 shown, this device includes:

[0091] An acquisition module 501, which is used to acquire aircraft performance parameters;

[0092] A throttle adjustment module 502, which is used to control the working state of the throttle device according to the aircraft performance parameters, so that the throttle device controls the flow rate of the main intake air flow entering the core driven fan;

[0093] A pre-whirl adjustment module 503, which is used to control the working state of the adjustable-opening pre-whirl valve according to the aircraft performance parameters and the working state of the throttle device, so that the adjustable-opening pre-whirl valve adjusts the flow rate of the anti-surge bleed air flow used to generate the pre-whirl air flow; the pre-whirl air flow converges into the main intake air flow; the anti-surge bleed air flow is discharged from the intermediate stage of the high-pressure compressor;

[0094] A bleed adjustment module 504, which is used to control the working state of the adjustable-opening bleed valve according to the anti-surge result of the adjustable-opening pre-whirl valve, so that the adjustable-opening bleed valve controls the flow rate of the anti-surge bleed air flow discharged into the bypass duct.

[0095] In an optional implementation manner, the pre-whirl adjustment module is further used for:

[0096] Acquiring the performance parameters of the converged air flow after the main intake air flow and the pre-whirl air flow converge;

[0097] Calculating the positive angle of attack of the converged air flow entering the high-pressure compressor based on the performance parameters of the converged air flow;

[0098] Comparing the positive angle of attack of the intake air with a preset positive angle of attack of the intake air to adjust the opening of the adjustable-opening pre-whirl valve;

[0099] The bleed adjustment module is further used for:

[0100] Adjusting the opening of the adjustable-opening bleed valve based on the anti-surge result of the adjustable-opening pre-whirl valve.

[0101] In an optional implementation manner, the pre-whirl adjustment module is further used for:

[0102] When the intake positive angle of attack is greater than the preset intake positive angle of attack, increase the opening degree of the adjustable opening pre-whirl valve;

[0103] The bleed air adjustment module is further configured to:

[0104] When the anti-surge result of the adjustable opening pre-whirl valve does not meet the preset conditions, increase the opening degree of the adjustable opening bleed air valve.

[0105] The further function descriptions of the above-mentioned various modules and units are the same as those in the corresponding above-mentioned embodiments, and will not be elaborated here.

[0106] The anti-surge device for driving a fan by the core engine of the variable cycle engine in this embodiment is presented in the form of functional units. Here, the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and a memory that execute one or more software or fixed programs, and / or other devices that can provide the above functions.

[0107] An embodiment of the present invention further provides a computer device having the above-mentioned Figure 5 shown anti-surge device for driving a fan by the core engine of the variable cycle engine.

[0108] Please refer to Figure 6 , Figure 6 which is a schematic structural diagram of a computer device provided by an optional embodiment of the present invention. As Figure 6 shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including a high-speed interface and a low-speed interface. Each component communicates with each other using different buses and can be installed on a common motherboard or installed in other ways as needed. The processor can process instructions executed within the computer device, including instructions stored in the memory or on the memory to display graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (such as an array of servers, a set of blade servers, or a multi-processor system). Figure 6 In

[0109] The processor 10 may be a central processing unit, a network processor, or a combination thereof. Among them, the processor 10 may further include a hardware chip. The above-mentioned hardware chip may be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The above-mentioned programmable logic device may be a complex programmable logic device, a field-programmable gate array, a generic array logic, or any combination thereof.

[0110] Among them, the memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiments.

[0111] The memory 20 may include a program storage area and a data storage area. Among them, the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may further include a non-transitory memory, such as at least one disk storage device, a flash memory device, or other non-transitory solid-state storage devices. In some alternative embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device through a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an enterprise intranet, a local area network, a mobile communication network, and combinations thereof.

[0112] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk, or a solid-state drive; the memory 20 may further include a combination of the above types of memories.

[0113] The computer device further includes a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0114] The embodiments of the present invention further provide a computer-readable storage medium. The method according to the embodiments of the present invention can be implemented in hardware, firmware, or be implemented as computer code that can be recorded on a storage medium, or be implemented as computer code originally stored in a remote storage medium or a non-transitory machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium may be a magnetic disk, an optical disk, a read-only memory, a random access memory, a flash memory, a hard disk, or a solid-state drive, etc.; further, the storage medium may further include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by the computer, the processor, or the hardware, the method shown in the above embodiments is implemented.

[0115] A part of the present invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the present invention through the operations of the computer. Those skilled in the art should understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executes the instructions, or the computer compiles the instructions and then executes the corresponding compiled program, or the computer reads and executes the instructions, or the computer reads and installs the instructions and then executes the corresponding installed program. Herein, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible by the computer.

[0116] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the protection scope of the present invention.

Claims

1. A variable cycle engine core engine-driven fan anti-surge system, characterized in that, The anti-surge system includes: An engine electronic control system for controlling the working state of a throttle device, the working state of an adjustable-opening pre-whirl valve, and the working state of an adjustable-opening bleed valve according to aircraft performance parameters; The throttle device is electrically connected to the engine electronic control system and is used to control the flow rate of the main intake air flow entering the core engine-driven fan according to the instructions of the engine electronic control system; The adjustable-opening pre-whirl valve is electrically connected to the engine electronic control system and is used to control the flow rate of the anti-surge bleed air flow for generating pre-whirl air flow according to the instructions of the engine electronic control system; the pre-whirl air flow merges into the main intake air flow; the anti-surge bleed air flow is discharged from the intermediate stage of the high-pressure compressor; The adjustable-opening bleed valve is electrically connected to the engine electronic control system and is used to control the flow rate of the anti-surge bleed air flow discharged into the bypass duct according to the instructions of the engine electronic control system.

2. The anti-surge system according to claim 1, characterized in that The anti-surge system further includes a pre-whirl air flow generator; The pre-whirl air flow generator is used to generate pre-whirl air flow according to the anti-surge bleed air flow discharged by the adjustable-opening pre-whirl valve and merge the pre-whirl air flow into the main intake air flow.

3. The anti-surge system according to claim 2, characterized in that, The anti-surge system further includes a gas supply chamber; The gas supply chamber is used to store the anti-surge bleed air flow discharged from the intermediate stage of the high-pressure compressor and discharge the anti-surge bleed air flow into the pre-whirl air flow generator through the adjustable-opening pre-whirl valve; or discharge the anti-surge bleed air flow into the bypass duct through the adjustable-opening bleed valve.

4. A method for preventing surge of a fan driven by a core engine of a variable cycle engine, characterized in that, An engine electronic control system applied to the anti-surge system of a core engine-driven fan of a variable cycle engine, the method includes: Obtain aircraft performance parameters; According to the aircraft performance parameters, control the working state of the throttle device so that the throttle device controls the flow rate of the main intake air flow entering the core engine-driven fan; According to the aircraft performance parameters and the working state of the throttle device, control the working state of the adjustable-opening pre-whirl valve so that the adjustable-opening pre-whirl valve adjusts the flow rate of the anti-surge bleed air flow for generating pre-whirl air flow; the pre-whirl air flow merges into the main intake air flow; the anti-surge bleed air flow is discharged from the intermediate stage of the high-pressure compressor; According to the anti-surge result of the adjustable-opening pre-whirl valve, control the working state of the adjustable-opening bleed valve so that the adjustable-opening bleed valve controls the flow rate of the anti-surge bleed air flow discharged into the bypass duct.

5. The method according to claim 4, wherein The controlling the working state of the adjustable-opening pre-whirl valve according to the aircraft performance parameters and the working state of the throttle device includes: Obtain the performance parameters of the combined air flow after the main intake air flow and the pre-whirl air flow are combined; Based on the performance parameters of the combined air flow, calculate the positive angle of attack of the combined air flow entering the high-pressure compressor; Compare the positive angle of attack of the intake air with a preset positive angle of attack of the intake air to adjust the opening degree of the adjustable-opening pre-whirl valve; The controlling the working state of the adjustable-opening bleed valve according to the anti-surge result of the adjustable-opening pre-whirl valve includes: Based on the anti-surge result of the adjustable-opening pre-whirl valve, adjust the opening degree of the adjustable-opening bleed valve.

6. The method according to claim 5, wherein The adjusting the opening degree of the adjustable-opening pre-whirl valve includes: When the intake positive angle of attack is greater than the preset intake positive angle of attack, increase the opening degree of the adjustable opening pre-whirl valve; Controlling the opening degree of the adjustable opening bleed valve includes: When the anti-surge result of the adjustable opening pre-whirl valve does not meet the preset conditions, increase the opening degree of the adjustable opening bleed valve.

7. A variable cycle engine core engine driven fan anti-surge device, characterized in that Applied to the engine electronic control system in the variable cycle engine core engine driven fan anti-surge system, the device includes: An acquisition module for acquiring aircraft performance parameters; A throttle adjustment module for controlling the working state of the throttle device according to the aircraft performance parameters, so that the throttle device controls the flow rate of the main intake air flow entering the core engine driven fan; A pre-whirl adjustment module for controlling the working state of the adjustable opening pre-whirl valve according to the aircraft performance parameters and the working state of the throttle device, so that the adjustable opening pre-whirl valve adjusts the flow rate of the anti-surge bleed air flow used to generate the pre-whirl air flow; the pre-whirl air flow merges into the main intake air flow; the anti-surge bleed air flow is discharged from the intermediate stage of the high-pressure compressor; A bleed adjustment module for controlling the working state of the adjustable opening bleed valve according to the anti-surge result of the adjustable opening pre-whirl valve, so that the adjustable opening bleed valve controls the flow rate of the anti-surge bleed air flow discharged into the bypass duct.

8. A computer device, characterized in that, Including: A memory and a processor, which are communicatively connected to each other. The memory stores computer instructions, and the processor executes the computer instructions to execute the variable cycle engine core engine driven fan anti-surge method according to any one of claims 4 to 6.

9. A computer-readable storage medium, characterized in that, Computer instructions are stored on the computer-readable storage medium, and the computer instructions are used to cause the computer to execute the variable cycle engine core engine driven fan anti-surge method according to any one of claims 4 to 6.

10. A computer program product, characterized in that, Including computer instructions, which are used to cause the computer to execute the variable cycle engine core engine driven fan anti-surge method according to any one of claims 4 to 6.

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