A method and system for testing a dynamic variable speed inlet under continuous bleed conditions

Abstract

The present application belongs to the technical field of test environment construction of aero-engine components, and provides a dynamic variable-speed inlet test method and system under continuous air supply and extraction conditions, the method comprising: constructing a nozzle profile, a test device nozzle inlet and outlet pressure ratio, and a speed-continuous adjustment sub-model of air supply and extraction pressure and flow balance; inputting the dynamic change requirement of the target speed with time during continuous variable-speed test under non-stop air condition into each control sub-model, combining the control law of each actuator, establishing a variable-speed control model of the nozzle profile, the test device nozzle inlet and outlet pressure ratio, the air supply and extraction pressure balance, and the test piece attitude with time, and performing continuous variable-speed flow field under the conditions of uninterrupted air supply and extraction to meet the variable-speed and time requirements. The method can perform speed-continuous dynamic change blowing test under the conditions of non-stop air and uninterrupted test device operation, and provides reliable test data support for advanced aircraft inlet design and optimization.

Description

Technical Field

[0001] This invention belongs to the technical field of test environment construction for aero-engine components, and relates to a dynamic variable speed inlet test method and system under continuous air supply and extraction conditions. The method is to conduct a dynamic variable speed continuous test of the inlet in the mode of changing the corresponding nozzle profile without stopping the air supply. Background Technology

[0002] As the "breathing passage" of modern air-breathing aircraft, the air intake needs to capture and initially compress the oxidizer (O2) necessary for combustion during flight. The captured airflow and the quality of the airflow field at the air intake exit must meet corresponding requirements to ensure that the engine continuously and stably provides flight power. In critical and high-risk mission phases of aircraft, flight speed and attitude change continuously according to mission requirements, and the airflow captured by the air intake and the quality of the airflow field at the exit vary significantly. This has a crucial impact on the stable operation of the engine and the continuity of thrust, and is one of the keys to the successful completion of the flight mission.

[0003] In the working envelope of modern aircraft air intakes, flight speeds are typically supersonic or higher. Therefore, a key aspect of conducting air intake tests is simulating and constructing a flow field where airflow speeds exceed the local speed of sound. This requires wind tunnels equipped with nozzles designed for different exit airflow velocities. According to aerodynamic principles, when the airflow speed is below the local speed of sound, a contracting nozzle is used, and the inlet gas pressure is adjusted via valves to regulate the airflow speed. However, when the tested airflow speed exceeds the speed of sound, gas pressure is no longer the sole determining factor for regulating airflow speed. A Laval nozzle with a flow channel cross-section that first contracts and then expands must also be used. Therefore, constructing a supersonic flow field requires adjusting the nozzle profile while simultaneously adjusting the pressure, unlike in low-speed wind tunnels where airflow speed can be adjusted simply by regulating the incoming flow pressure.

[0004] Traditional wind tunnel tests of inlet performance exceeding local sonic speeds are constant-velocity steady-state inlet blowing tests. These tests obtain the steady-state performance of the inlet through a series of discrete tests at fixed velocities, attitude angles, and internal geometric characteristics. The operational procedure is as follows: Before the test, the nozzle profile corresponding to the test airflow velocity is installed or adjusted; after the test begins, the nozzle inlet pressure section is adjusted to establish the flow field corresponding to the required airflow velocity; after adjusting the attitude angle and other geometric parameters, test data is recorded; the nozzle inlet air supply is cut off, and the nozzle profile corresponding to the next airflow velocity is replaced or adjusted; the test is then conducted under the next airflow velocity condition. This method typically requires stopping the airflow, releasing the seal, adjusting the flow channel profile, sealing again, supplying air, and adjusting the pressure to obtain a new velocity flow field before conducting the test.

[0005] With the development of technologies in the aviation and aerospace industries, flight parameters change drastically during critical and high-risk missions such as takeoff, landing, climb, dive, and dogfights. The risks and difficulties of maintaining stable and continuous engine power output are significantly higher than under steady-state and constant-speed conditions. Under these circumstances, the performance of the air intake also deteriorates significantly. Performance data obtained from constant-speed steady-state blowing tests deviate from actual flight performance, leading to discrepancies in the air intake-engine matching and the overall aircraft-engine matching. This data no longer meets the needs of researchers to obtain and evaluate the dynamic performance and flow field characteristics of the air intake under continuously varying flight speeds. Therefore, it is necessary to conduct dynamic performance tests of the air intake under continuously varying speeds to obtain performance parameters and their variation patterns that conform to the actual operating conditions of the air intake.

[0006] However, traditional testing equipment and methods face two main difficulties in conducting continuous and dynamically changing speed tests within the supersonic speed range. Firstly, speed control in traditional inlet tests is achieved by altering the nozzle profile and matching the inlet-outlet pressure ratio. The nozzle profile, inlet / outlet pressure, and flow rate are interconnected, making the dynamic parameter matching process demanding high speed and precision, difficult to implement, and fraught with testing risks. Secondly, wind tunnels employing high-pressure gas tank supply and vacuum tank extraction methods require extremely high construction and operating costs to meet the demands of long-duration, high-speed, and large-aperture operation. A continuous gas supply and extraction operation mode is preferable; however, the gas supply and extraction units ensuring test operation are large, high-value equipment. Rapidly adjusting their operating conditions according to changes in test speed, pressure, and flow rate is extremely difficult and has a severe negative impact on the unit's lifespan, resulting in very high testing costs and risks.

[0007] Therefore, there is an urgent need to develop a dynamic testing method for air intakes that meets the requirements of continuous speed variation. Summary of the Invention

[0008] To address the high operating costs, significant risks, and large result deviations associated with traditional methods that typically require stopping the gas supply, releasing the seal, adjusting the flow channel profile, resealing, supplying gas, and regulating pressure before obtaining a new velocity flow field for testing, this invention discloses a method for testing air intakes under continuous gas supply and extraction conditions. This method conducts dynamic inlet velocity variation tests on air intake characteristics in an uninterrupted gas supply operation mode, providing reliable experimental data support for the design and optimization of advanced aircraft air intakes. The method includes the following steps:

[0009] Sub-model construction: Based on the requirements of test speed variation, sub-models are constructed for continuous adjustment of nozzle profile with speed, continuous adjustment of nozzle inlet and outlet pressure ratio with speed, and continuous adjustment of supply and extraction pressure and flow rate with speed to maintain balance.

[0010] Generate variable speed control model: Obtain the dynamic change law of the target speed over time when performing variable speed test under continuous air supply conditions, input the dynamic change law into each of the sub-models, and combine the control law of the actuator corresponding to each sub-model to establish variable speed control models for the change of nozzle profile over time, the change of pressure ratio between nozzle inlet and outlet of the test instrument over time, the change of maintaining the balance of supply and extraction pressure and flow over time, and the change of test piece attitude over time.

[0011] Continuous variable speed blowing test: Under the condition of continuous air supply and extraction, the flexible wall nozzle profile drive device, main regulating valve group, air supply and extraction regulating valve group, and attitude adjustment drive device are synchronously adjusted through all the aforementioned variable speed control models to make the nozzle profile and the nozzle inlet and outlet pressure ratio change synchronously and in coordination. At the same time, the pressure and flow rate of air supply and extraction are kept in balance to construct a continuous variable speed flow field with variable speed range and time controllable. The test is carried out with the inlet velocity of the air inlet exceeding the local speed of sound and continuously changing dynamically, and dynamic test data is collected synchronously.

[0012] Furthermore, a sub-model is constructed in which the nozzle profile is continuously adjusted with velocity, including:

[0013] Based on the Laval nozzle throat area formula and the variation of nozzle profile with exit airflow velocity, the nozzle throat height and the heights of various control points on the profile are obtained. A functional relationship between the nozzle profile height and Mach number is established, expressed as:

[0014] ;

[0015] Where ht(Ma) is a curve function of the nozzle throat height as a function of the exit airflow velocity, he is the nozzle exit height, Ma is the exit airflow velocity, and k is the specific heat ratio of air. The boundary layer correction coefficient is the result of CFD simulation and adjustment of each control point along the nozzle axis.

[0016] Furthermore, a sub-model is constructed to continuously adjust the inlet and outlet pressure ratio of the test nozzle with velocity, including:

[0017] Based on aerodynamic principles and the constraints of the supply and exhaust pressure adjustment range of the experimental system, a functional relationship is established between the ratio of the critical total pressure in the pre-nozzle stable section to the static pressure at the nozzle exit and the change in exit airflow velocity, expressed as:

[0018] ;

[0019] in, Ma Let π be the outlet airflow velocity. Ma ) is a function of the ratio of the critical total pressure in the pre-nozzle stabilization section to the static pressure at the nozzle exit. This is the critical total pressure in the stabilization section before the nozzle. PThis refers to the static pressure at the nozzle exit. The total pressure correction factor is the one obtained after CFD simulation and debugging correction of a given nozzle system.

[0020] Furthermore, a sub-model is constructed to maintain the balance between supply and extraction pressures and continuously adjust them with velocity, including:

[0021] Based on the regulating characteristics of the valve system and the aerodynamic characteristics of the nozzle and exhaust diffuser, it is established that when the mainstream flow rate changes, the operating state of the air supply unit and the air extraction unit remains constant by adjusting the inlet regulating valve group and the extraction regulating valve group. Through supply and extraction balance regulation, the absolute values ​​of the flow rate changes of the vent valve caused by the mainstream velocity change are equal to the mainstream flow rate change, and the absolute values ​​of the mainstream flow rate change and the replenishment valve flow rate change are opposite. After achieving balance, the pressure and flow rate at the air supply end and the pressure and flow rate at the extraction end of the test apparatus remain essentially constant.

[0022] Furthermore, a variable speed control model for the nozzle profile over time is established, including:

[0023] The dynamic change law and the control law of the flexible wall nozzle actuator are input into the sub-model of the nozzle profile continuously adjusted with speed. Simulation calculation is performed to obtain the displacement command of each actuator of the flexible wall nozzle profile driving device at each moment, and the speed control model of the nozzle profile over time is obtained.

[0024] Furthermore, a variable-speed control model for the inlet and outlet pressure ratio of the test nozzle over time is established, including:

[0025] Using the aerodynamic characteristics of the nozzle and the system boundary conditions as constraints, the dynamic change law is input into the sub-model of the nozzle inlet and outlet pressure ratio of the test instrument continuously adjusted with velocity. The ratio of the critical total pressure in the stable section before the nozzle to the static pressure at the nozzle outlet at any time is calculated to obtain the variable speed control model of the nozzle inlet and outlet pressure ratio of the test instrument over time. The system boundary conditions include the gas supply system boundary and the gas extraction system boundary.

[0026] Furthermore, a variable speed control model is established to maintain the balance between supply and extraction pressure and flow rate over time, including:

[0027] The dynamic change law and the control law of the valve system actuator are input into the sub-model of continuous adjustment of the supply and extraction pressure balance with speed. Joint simulation is performed to obtain the opening change law of each regulating valve during the continuous change of the mainstream speed and flow rate, so as to maintain the stable operation of the supply and extraction units. Under the premise of maintaining the balance of supply and extraction pressure and flow rate, the variable speed control model of each valve system over time is obtained.

[0028] Furthermore, a variable speed control model for the attitude of the test specimen over time is established, including:

[0029] The dynamic change law is input into the change law of the test specimen's attitude with Mach number in the preset test conditions. Based on the kinematic and dynamic control law of the attitude adjustment mechanism, the control commands of the angle and angular velocity of the test specimen's attitude adjustment mechanism in each degree of freedom with time are obtained, and the variable speed control model of the test specimen's attitude with time is obtained.

[0030] Furthermore, tests were conducted where the inlet velocity of the air intake exceeded the local speed of sound and varied continuously, including:

[0031] The equipment is started and initial operating condition is adjusted to stabilize the test airflow velocity within the given initial test nozzle outlet airflow velocity range;

[0032] In the initial state, the control model parameters are input into each subsystem, the data acquisition system is started, and a dynamic characteristic test with continuous variable speed is carried out, simultaneously recording dynamic test data of continuous changes in test speed, attitude angle, and internal geometric adjustment of the test piece;

[0033] After the test, gradually withdraw from the gas supply and extraction commissioning state and stop system operation.

[0034] This invention also provides a dynamic variable speed inlet test system for implementing the above method under continuous air supply and extraction conditions. The system includes an inlet regulating valve group, a diffuser section, a stabilizing section, a converging section, a flexible wall nozzle, a test chamber, an inlet test piece, an attitude adjustment mechanism, an exhaust diffuser, and an extraction regulating valve group. The system adopts a front-supply and rear-extraction working mode to continuously and dynamically adjust the flexible wall nozzle profile, continuously control the nozzle inlet and outlet pressure ratio, and regulate the flow of the vent valve group and the make-up air valve group, thereby establishing a dynamic test flow field in which the inlet velocity of the inlet exceeds the local speed of sound and changes continuously.

[0035] The flexible wall nozzle is made of flexible steel plate and equipped with multiple sets of flexible wall nozzle actuators to achieve remote continuous adjustment of the nozzle flow channel profile without interrupting airflow.

[0036] The intake regulating valve assembly adjusts the pressure and flow balance at the supply end when the mainstream flow changes, and the extraction regulating valve assembly adjusts the pressure and flow balance at the extraction end when the mainstream flow changes.

[0037] The method of this invention enables the inlet test speed variation to be comparable to the actual flight conditions of the aircraft, and the adjustment speed and accuracy of the nozzle profile and nozzle pressure ratio are matched with the requirements of the test airflow speed variation. To reduce operational risks and costs, it ensures that the large air compressor unit for air supply and extraction during the test operation is in steady-state operation or in an acceptable slow-speed, small-amplitude variable-condition operation. This ability to conduct tests exceeding the local speed of sound and with continuously varying speeds under continuous air supply and extraction conditions provides support for the design verification and optimization of the dynamic performance of advanced aircraft inlets. In general, it has the following advantages:

[0038] 1. It enables dynamic testing with continuous changes in intake velocity, eliminating the need to stop the airflow and replace the nozzle, thus significantly improving testing efficiency;

[0039] 2. Through multi-parameter coordinated control, large-scale air supply and extraction units are ensured to operate under stable conditions, reducing equipment wear and operating costs;

[0040] 3. To more realistically simulate the variable speed flight conditions of an aircraft, obtain dynamic performance parameters of the air intake, and improve the accuracy of design verification;

[0041] 4. Supports long-term continuous testing, suitable for flow field characteristic research and instability characteristic analysis of high-risk flight missions. Attached Figure Description

[0042] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a flowchart of the dynamic variable speed intake duct test method under continuous air supply and extraction conditions according to the present invention;

[0044] Figure 2 This is a schematic diagram of the dynamic variable speed intake duct test system under continuous air supply and extraction conditions according to the present invention.

[0045] Figure 3 This is a schematic diagram of the test section;

[0046] Among them, 1. Intake regulating valve assembly; 2. Diffuser section; 3. Stabilizing section; 4. Converging section; 5. Flexible wall nozzle; 51. Flexible wall nozzle actuator; 52. Flexible steel plate; 6. Test chamber; 7. Intake duct test piece; 8. Attitude adjustment mechanism; 9. Exhaust diffuser; 10. Extraction regulating valve assembly. Detailed Implementation

[0047] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0048] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. This application can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. It should be noted that, in the absence of conflict, the following embodiments and features of the embodiments can be combined with each other. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0049] This invention discloses a test method for a dynamic variable-velocity inlet under continuous air supply and extraction conditions. The method involves conducting inlet characteristic tests with dynamically changing incoming flow velocity in an uninterrupted air supply operation mode to obtain dynamic performance parameters of the inlet under variable-velocity flight conditions, providing reliable experimental data support for the design and optimization of advanced aircraft inlets. See also... Figure 1 As shown, the method includes the following steps:

[0050] Sub-model construction: Based on the requirements of test speed variation, sub-models are constructed for continuous adjustment of nozzle profile with speed, continuous adjustment of nozzle inlet and outlet pressure ratio with speed, and continuous adjustment of supply and extraction pressure and flow rate with speed to maintain balance.

[0051] Generate variable speed control models: Obtain the dynamic change law of the target speed over time when conducting variable speed tests under continuous gas supply conditions. Input the dynamic change law into each of the sub-models. Combine the control law of the actuators corresponding to each sub-model to establish variable speed control models for the changes of nozzle profile over time, the changes of nozzle inlet and outlet pressure ratio over time, the changes of maintaining supply and extraction pressure and flow balance over time, and the changes of test piece attitude over time. The actuators include the flexible wall nozzle actuator, the test piece main regulating valve system actuator, the supply balance regulating valve system actuator, the extraction balance regulating valve system actuator, and the attitude adjustment actuators of the test piece in each dimension. Each variable speed control model includes the control law and control target parameters of all actuators under each time series.

[0052] Continuous variable speed blowing test: Under the condition of continuous air supply and extraction, the flexible wall nozzle profile drive device, main regulating valve group, air supply and extraction regulating valve group, and attitude adjustment drive device are synchronously adjusted through all the aforementioned variable speed control models to make the nozzle profile and the nozzle inlet and outlet pressure ratio change synchronously and in coordination. At the same time, the pressure and flow rate of air supply and extraction are kept in balance to construct a continuous variable speed flow field with variable speed range and time controllable. The test is carried out with the inlet velocity of the air inlet exceeding the local speed of sound and continuously changing dynamically, and dynamic test data is collected synchronously.

[0053] Furthermore, a sub-model is constructed in which the nozzle profile is continuously adjusted with velocity, including:

[0054] Based on the Laval nozzle throat area formula and the variation of nozzle profile with exit airflow velocity, the nozzle throat height and the heights of various control points on the profile are obtained. A functional relationship between the nozzle profile height and Mach number is established, expressed as:

[0055] ;

[0056] Where ht(Ma) is a curve function of the nozzle throat height as a function of the exit airflow velocity, he is the nozzle exit height, Ma is the exit airflow velocity, and k is the specific heat ratio of air. The boundary layer correction coefficient is the result of CFD simulation and adjustment of each control point along the nozzle axis.

[0057] The formula for the throat area of ​​a Laval nozzle flow channel is:

[0058] ;

[0059] In the above formula:

[0060] It is a flow function and can be calculated from the nozzle outlet airflow velocity and the specific heat ratio of air;

[0061] Ma is the outlet airflow velocity, a dimensionless parameter relative to the local speed of sound;

[0062] The curve of nozzle throat height as a function of Ma is obtained through theory, CFD simulation, and debugging correction.

[0063] This refers to the nozzle exit height.

[0064] Meanwhile, based on aerodynamic design, CFD verification and debugging, the nozzle profile curve corresponding to speed Ma is as follows:

[0065] , where x1, ..., x n， The displacement of each drive point of the nozzle profile corresponding to the speed (Ma).

[0066] Furthermore, a sub-model is constructed to continuously adjust the inlet and outlet pressure ratio of the test nozzle with velocity, including:

[0067] Based on aerodynamic principles and the constraints of the supply and exhaust pressure adjustment range of the experimental system, a functional relationship is established between the ratio of the critical total pressure in the pre-nozzle stable section to the static pressure at the nozzle exit and the change in exit airflow velocity, expressed as:

[0068] ;

[0069] in, Ma Let π be the nozzle exit airflow velocity. Ma ) is a function of the ratio of the critical total pressure in the nozzle front stabilization section to the static pressure at the nozzle exit. This is the critical total pressure in the stabilization section before the nozzle. P Let f(Ma) be the nozzle exit static pressure, and f(Ma) be the total static pressure ratio function at the corresponding exit airflow velocity. For a given nozzle, the total pressure correction factor is obtained after CFD simulation and debugging of the system.

[0070] The formula for the principle of aerodynamics is:

[0071] .

[0072] Furthermore, the absolute values ​​of the flow rate changes at the vent valve and the mainstream flow rate, as well as the flow rate changes at the mainstream and replenishment valves, caused by the change in mainstream velocity, are equal but in opposite directions. This ensures that the pressure and flow rate at the supply end and the pressure and flow rate at the extraction end of the test apparatus remain essentially constant after achieving equilibrium. Specifically, a sub-model is constructed to maintain the balance between supply and extraction pressures and continuously adjust them with velocity, including:

[0073] Based on the regulating characteristics of the valve system and the aerodynamic characteristics of the nozzle and exhaust diffuser, it is established that when the mainstream flow changes, the operating state of the air supply unit and the air extraction unit can be kept constant by adjusting the intake regulating valve group and the extraction regulating valve group.

[0074] Furthermore, the dynamic change law of the target speed over time, Ma(t), during the variable speed test under continuous gas supply conditions is the target of the control model. It can be obtained according to the test speed requirements (variable speed range, time, and speed law), and is a condition known before the test.

[0075] Furthermore, a variable speed control model for the nozzle profile over time is established, including:

[0076] The dynamic variation law and the control law of the flexible wall nozzle actuator are input into a sub-model for continuous velocity adjustment of the nozzle profile. Through simulation calculations, the displacement commands of each actuator in the flexible wall nozzle actuator at each moment are obtained, resulting in a velocity-time-dependent control model of the nozzle profile. Specifically, the velocity-time-dependent control model of the nozzle profile is established by inputting Ma(t) of different time series into the velocity-dependent control model of the nozzle profile. .

[0077] Furthermore, a variable-speed control model for the inlet and outlet pressure ratio of the test nozzle over time was established. ,include:

[0078] Using the aerodynamic characteristics of the nozzle and the system boundary conditions as constraints, the dynamic change law is input into the sub-model of the nozzle inlet and outlet pressure ratio of the test instrument continuously adjusted with velocity. The ratio of the critical total pressure in the stable section before the nozzle to the static pressure at the nozzle outlet at any time is calculated to obtain the variable speed control model of the nozzle inlet and outlet pressure ratio of the test instrument over time. The system boundary conditions include the gas supply system boundary and the gas extraction system boundary.

[0079] Furthermore, a variable speed control model is established to maintain the balance between supply and extraction pressure and flow rate over time. ,include:

[0080] The dynamic change law and the control law of the valve system actuator are input into the sub-model of continuous adjustment of the supply and extraction pressure balance with speed. Joint simulation is performed to obtain the opening change law of each regulating valve during the continuous change of the mainstream speed and flow rate to maintain the stable operation of the supply and extraction units. Under the premise of maintaining the balance of supply and extraction pressure and flow rate, the variable speed control model of each valve system over time is obtained.

[0081] Furthermore, a variable speed control model for the attitude of the test specimen over time was established. , ,include:

[0082] The dynamic change law is input into the preset test conditions to show the change law of the test specimen's attitude with Mach number (including the change law of the test specimen's attitude with Ma). and In this study, based on the kinematic and dynamic control laws of the attitude adjustment mechanism, control commands for the angle and angular velocity of the attitude adjustment mechanism of the test specimen in each degree of freedom as a function of time are obtained, thus obtaining the variable speed control model of the attitude of the test specimen over time.

[0083] Furthermore, after the above-mentioned control models are established, a full wind tunnel non-ventilated semi-physical simulation method can be used to dynamically assess the compliance of each actuator with the control model, the synchronization status, and the compliance of the test speed with the input speed change law. If necessary, the control parameters of each sub-model can be adjusted to optimize the control model.

[0084] Furthermore, tests were conducted where the inlet velocity of the air intake exceeded the local speed of sound and varied continuously, including:

[0085] The equipment is started and initial operating condition is adjusted to stabilize the test airflow velocity within the given initial outlet airflow velocity range;

[0086] In the initial state, the control model parameters are input into each subsystem, the data acquisition system is started, and a dynamic characteristic test with continuous variable speed is carried out, simultaneously recording dynamic test data of continuous changes in test speed, attitude angle, and internal geometric adjustment of the test piece;

[0087] After the test, gradually withdraw from the gas supply and extraction commissioning state and stop system operation.

[0088] This invention also provides a dynamic variable speed inlet test system for implementing the above method under continuous air supply and extraction conditions, see [link to relevant documentation]. Figure 2 As shown, the system includes an intake regulating valve assembly 1, a diffuser section 2, a stabilizing section 3, a convergent section 4, a flexible-wall nozzle 5, a test chamber 6, an intake duct test piece 7, an attitude adjustment mechanism 8, an exhaust diffuser 9, and an extraction regulating valve assembly 10. The system adopts a front-supply, rear-extraction working mode to continuously and dynamically adjust the flexible-wall nozzle profile, continuously control the nozzle inlet and outlet pressure ratio, and regulate the flow rates of the vent valve assembly and the supplementary air valve assembly, establishing a dynamic test flow field where the inlet velocity of the intake duct exceeds the local speed of sound and changes continuously.

[0089] See Figure 3 As shown, the flexible wall nozzle 5 is made of flexible steel plate 52 and is equipped with multiple sets of flexible wall nozzle actuators 51 to achieve remote continuous adjustment of the nozzle flow channel profile under the condition of no air interruption.

[0090] The intake regulating valve group 1 adjusts the pressure and flow balance at the supply end when the mainstream flow changes, and the extraction regulating valve group 10 adjusts the pressure and flow balance at the extraction end when the mainstream flow changes.

[0091] The method of this invention enables the inlet test speed variation to be comparable to the actual flight conditions of the aircraft, and the adjustment speed and accuracy of the nozzle profile and nozzle pressure ratio are matched with the requirements of the test airflow speed variation. To reduce operational risks and costs, it ensures that the large air compressor unit for air supply and extraction during the test operation is in steady-state operation or in an acceptable slow-speed, small-amplitude variable-condition operation. This ability to conduct tests exceeding the local speed of sound and with continuously varying speeds under continuous air supply and extraction conditions provides support for the design verification and optimization of the dynamic performance of advanced aircraft inlets. In general, it has the following advantages:

[0092] 1. It enables dynamic testing with continuous changes in intake velocity, eliminating the need to stop the airflow and replace the nozzle, thus significantly improving testing efficiency;

[0093] 2. Through multi-parameter coordinated control, large-scale air supply and extraction units are ensured to operate under stable conditions, reducing equipment wear and operating costs;

[0094] 3. To more realistically simulate the variable speed flight conditions of an aircraft, obtain dynamic performance parameters of the air intake, and improve the accuracy of design verification;

[0095] 4. Supports long-term continuous testing, suitable for flow field characteristic research and instability characteristic analysis of high-risk flight missions.

[0096] In this embodiment, a computer device is also provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above-described dynamic variable speed intake test method under any continuous air supply and extraction conditions.

[0097] Specifically, the computer device can be a computer terminal, a server, or a similar computing device.

[0098] In this embodiment, a computer-readable storage medium is provided, which stores a computer program for executing any of the above-described dynamic variable speed intake duct test methods under continuous air supply and extraction conditions.

[0099] Specifically, computer-readable storage media, including both permanent and non-permanent, removable and non-removable media, can store information using any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer-readable storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable storage media does not include transient media, such as modulated data signals and carrier waves.

[0100] Obviously, those skilled in the art should understand that the modules or steps of the above-described embodiments of the present invention can be implemented using general-purpose computing devices. They can be centralized on a single computing device or distributed across a network of multiple computing devices. Optionally, they can be implemented using computer-executable program code, thereby storing them in a storage device for execution by a computing device. In some cases, the steps shown or described can be performed in a different order than those presented here, or they can be fabricated as separate integrated circuit modules, or multiple modules or steps can be fabricated as a single integrated circuit module. Thus, the embodiments of the present invention are not limited to any particular hardware and software combination.

[0101] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, various modifications and variations can be made to the embodiments of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A test method for a dynamic variable speed intake duct under continuous air supply and extraction conditions, characterized in that, In intake duct testing, intake duct characteristics are tested under a continuous flow operation mode with dynamically changing incoming flow velocity. The method includes: Sub-model construction: Based on the requirements of test speed variation, sub-models are constructed for continuous adjustment of nozzle profile with speed, continuous adjustment of nozzle inlet and outlet pressure ratio with speed, and continuous adjustment of supply and extraction pressure and flow rate with speed to maintain balance. Generate variable speed control model: Obtain the dynamic change law of the target speed over time when performing variable speed test under continuous air supply conditions, input the dynamic change law into each of the sub-models, and combine the control law of the actuator corresponding to each sub-model to establish variable speed control models for the change of nozzle profile over time, the change of pressure ratio between nozzle inlet and outlet of the test instrument over time, the change of maintaining the balance of supply and extraction pressure and flow over time, and the change of test piece attitude over time. Continuous variable speed blowing test: Under the condition of continuous air supply and extraction, the flexible wall nozzle profile drive device, main regulating valve group, air supply and extraction regulating valve group, and attitude adjustment drive device are synchronously adjusted through all the variable speed control models to make the nozzle profile and the nozzle inlet and outlet pressure ratio change synchronously and in coordination. At the same time, the pressure and flow rate of air supply and extraction are kept in balance to construct a continuous variable speed flow field with variable speed range and time controllable. The test is carried out with the inlet velocity of the air inlet exceeding the local speed of sound and continuously changing dynamically, and dynamic test data is collected synchronously. Construct a sub-model where the nozzle profile continuously adjusts with velocity, including: Based on the Laval nozzle throat area formula and the variation of nozzle profile with exit gas velocity, the nozzle throat height and the heights of various control points on the profile are obtained. A functional relationship between the nozzle profile and Mach number is established, expressed as: ； Where ht(Ma) is a curve function of the nozzle throat height as a function of the exit airflow velocity, he is the nozzle exit height, Ma is the exit airflow velocity, and k is the specific heat ratio of air. The boundary layer correction coefficient is the result of CFD simulation and adjustment of each control point along the nozzle axis. A sub-model is constructed to continuously adjust the inlet and outlet pressure ratio of the test instrument nozzle with velocity, including: Based on aerodynamic principles and the constraints of the supply and exhaust pressure adjustment range of the experimental system, a functional relationship is established between the ratio of the critical total pressure in the pre-nozzle stable section to the static pressure at the nozzle exit and the change in exit airflow velocity, expressed as: ； in, Ma Let π be the outlet airflow velocity. Ma ) is a function of the ratio of the critical total pressure in the nozzle front stabilization section to the static pressure at the nozzle exit. This is the critical total pressure in the stabilization section before the nozzle. P This refers to the static pressure at the nozzle exit. The total pressure correction factor is obtained after CFD simulation and debugging of a given nozzle system. A sub-model is constructed to maintain the balance between supply and extraction pressures and continuously adjust them with velocity, including: Based on the regulating characteristics of the valve system and the aerodynamic characteristics of the nozzle and exhaust diffuser, it is established that when the mainstream flow changes, the operating state of the air supply unit and the air extraction unit can be kept constant by adjusting the intake regulating valve group and the extraction regulating valve group.

2. The test method for dynamic variable speed intake under continuous air supply and extraction conditions according to claim 1, characterized in that, Establish a variable speed control model for the nozzle profile over time, including: The dynamic change law and the control law of the flexible wall nozzle actuator are input into the sub-model of the nozzle profile continuously adjusted with speed. Simulation calculation is performed to obtain the displacement command of each actuator of the flexible wall nozzle profile driving device at each moment, and the speed control model of the nozzle profile over time is obtained.

3. The test method for dynamic variable speed intake under continuous air supply and extraction conditions according to claim 1, characterized in that, Establish a variable-speed control model for the inlet and outlet pressure ratio of the test nozzle over time, including: Using the aerodynamic characteristics of the nozzle and the system boundary conditions as constraints, the dynamic change law is input into the sub-model of the nozzle inlet and outlet pressure ratio of the test instrument continuously adjusted with velocity. The ratio of the critical total pressure in the stable section before the nozzle to the static pressure at the nozzle outlet at any time is calculated to obtain the variable speed control model of the nozzle inlet and outlet pressure ratio of the test instrument over time. The system boundary conditions include the gas supply system boundary and the gas extraction system boundary.

4. The test method for dynamic variable speed intake under continuous air supply and extraction conditions according to claim 1, characterized in that, Establish a variable-speed control model that maintains the balance between supply and extraction pressure and flow rate over time, including: The dynamic change law and the control law of the valve system actuator are input into the sub-model of continuous adjustment of the supply and extraction pressure balance with speed. Joint simulation is performed to obtain the opening change law of each regulating valve during the continuous change of the mainstream speed and flow rate, so as to maintain the stable operation of the supply and extraction units. Under the premise of maintaining the balance of supply and extraction pressure and flow rate, the variable speed control model of each valve system over time is obtained.

5. The test method for dynamic variable speed intake under continuous air supply and extraction conditions according to claim 1, characterized in that, Establish a variable-speed control model for the attitude of the test specimen over time, including: The dynamic change law is input into the change law of the test specimen's attitude with Mach number in the preset test conditions. Based on the kinematic and dynamic control law of the attitude adjustment mechanism, the control commands of the angle and angular velocity of the test specimen's attitude adjustment mechanism in each degree of freedom with time are obtained, and the variable speed control model of the test specimen's attitude with time is obtained.

6. The test method for dynamic variable speed intake under continuous air supply and extraction conditions according to claim 1, characterized in that, Conduct tests involving continuous dynamic changes in the air intake velocity exceeding the local speed of sound, including: The equipment is started and initial operating condition is adjusted to stabilize the test airflow velocity within the given initial test nozzle outlet airflow velocity range; In the initial state, the control model parameters are input into each subsystem, the data acquisition system is started, and a dynamic characteristic test with continuous variable speed is carried out, simultaneously recording dynamic test data of continuous changes in test speed, attitude angle, and internal geometric adjustment of the test piece; After the test, gradually withdraw from the gas supply and extraction commissioning state and stop system operation.

7. A dynamic variable speed inlet test system for implementing the method described in any one of claims 1-6 under continuous air supply and extraction conditions, characterized in that, The system includes an intake regulating valve assembly, a diffuser section, a stabilizing section, a convergent section, a flexible wall nozzle, a test chamber, an intake duct test piece, an attitude adjustment mechanism, an exhaust diffuser, and an extraction regulating valve assembly. The system adopts a front-supply and rear-extraction working mode to continuously and dynamically adjust the flexible wall nozzle profile, continuously control the nozzle inlet and outlet pressure ratio, and regulate the flow of the vent valve assembly and the supplementary air valve assembly, thereby establishing a dynamic test flow field in which the inlet velocity of the intake duct exceeds the local speed of sound and changes continuously. The flexible wall nozzle is made of flexible steel plate and equipped with multiple sets of flexible wall nozzle actuators to achieve remote continuous adjustment of the nozzle flow channel profile without interrupting airflow. The intake regulating valve assembly adjusts the pressure and flow balance at the supply end when the mainstream flow changes, and the extraction regulating valve assembly adjusts the pressure and flow balance at the extraction end when the mainstream flow changes.

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