Dynamic variable-speed air inlet channel test method and system under continuous air supply and exhaust condition

Abstract

The invention belongs to the technical field of aero-engine component test environment construction, and provides a dynamic variable speed air inlet channel test method and system under continuous air supply and exhaust conditions, and the method comprises the steps: constructing a spray pipe profile, a tester spray pipe inlet and outlet pressure ratio, air supply and exhaust pressure and a sub-model which is continuously adjusted along with the speed and is used for balancing the flow; inputting a dynamic change requirement of a target speed along with time in a continuous variable speed test under the condition of not stopping air supply into each control sub-model, and establishing a variable speed regulation model of a spray pipe profile, a pressure ratio of an inlet and an outlet of a tester spray pipe, air supply and exhaust pressure balance, a test piece posture and the like along with time in combination with a control rule of each execution mechanism; and a continuous variable-speed flow field meeting variable-speed and time requirements under the condition of uninterrupted air supply and extraction is carried out. According to the method, the blowing test with the speed continuously and dynamically changing can be carried out under the conditions of not stopping air supply and not interrupting operation of a tester, and reliable test data support is provided for design and optimization of an air inlet channel of an advanced aircraft.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of test environment construction of aero-engine components, and relates to a dynamic variable-speed inlet test method and system under continuous air extraction conditions. BACKGROUND

[0002] As the "breathing tract" of a modern air-breathing aircraft, the inlet needs to capture and preliminarily compress the oxidizer (O2) necessary for combustion in flight. The captured air flow and the inlet outlet flow field quality must meet the corresponding index requirements to ensure that the engine can continuously and stably provide flight power. In the key and high-risk task links of the aircraft, the flight speed and attitude continuously change according to the task requirements, the air flow captured by the inlet and the outlet flow field quality change greatly, which has a crucial influence on the stable work and thrust continuity of the engine, and is one of the keys to the successful completion of the flight task.

[0003] In the working envelope of a modern aircraft inlet, the flight speed is usually supersonic or higher, so a key to carrying out the inlet test is to simulate and build the flow field with a flow speed exceeding the local sound speed. Therefore, the wind tunnel needs to be equipped with nozzles with different designed outlet flow speeds. According to the aerodynamic principle, when the flow speed is lower than the local sound speed, a convergent nozzle needs to be used, and the gas pressure at the nozzle inlet needs to be adjusted by a valve to adjust the flow speed. However, when the test flow speed exceeds the sound speed, the gas pressure is no longer the only factor that determines the flow speed, and a Laval nozzle that converges and then diverges in the flow passage section needs to be used, so the flow field exceeding the sound speed needs to be built by adjusting the pressure and matching the nozzle profile, which is different from the case in a low-speed wind tunnel where the flow speed can be adjusted only by adjusting the incoming flow pressure.

[0004] The traditional wind tunnel carries out a steady-state inlet blowing test at a fixed speed exceeding the local sound speed, and obtains the steady-state performance of the inlet through a series of discrete fixed-speed, attitude angle and internal geometric feature state tests. The operation process is as follows: before the test, the nozzle profile corresponding to the test flow speed is installed or adjusted; after the test starts, the inlet pressure section is adjusted to establish a flow field corresponding to the required flow speed, the attitude angle and other geometric parameters are adjusted, and the test data is recorded; the inlet pressure section is cut off, the next nozzle profile corresponding to the flow speed is installed or adjusted, and the test under the next flow speed condition is carried out. This method usually needs to stop the air supply, remove the seal, adjust the flow passage profile, seal, supply the air, and adjust the pressure to obtain a new speed flow field before the test is carried out.

[0005] With the development of aviation and aerospace technology, in the key and high-risk task links of aircraft take-off, landing, climbing, diving and fighting, the flight parameters change rapidly, and the risk and difficulty of stable and continuous power output of the engine are significantly higher than those in the steady state and constant speed working condition. In this case, the performance of the inlet will also deteriorate significantly. The performance data obtained by the constant speed steady state blowing test deviates from the real flight performance, which makes the inlet-engine matching and the overall matching of the aircraft-engine also deviate, and cannot meet the needs of researchers to obtain and evaluate the dynamic performance and flow field characteristics of the inlet under the condition of continuous change of flight speed. Therefore, it is necessary to carry out dynamic performance test of the inlet with continuous change of speed to obtain the performance parameters and their change rules under the real working condition of the inlet.

[0006] However, there are two difficulties in carrying out continuous and dynamic speed test in the range of speed exceeding the sound speed by using traditional test devices and methods. On the one hand, the speed regulation of traditional inlet test is realized by changing the nozzle profile and matching the inlet and outlet pressure ratio. The nozzle profile, inlet and outlet pressure and flow rate influence each other, and the speed and accuracy requirements of the dynamic matching process of parameters are high, the realization difficulty is great, and the test risk is high. On the other hand, the wind tunnel using high-pressure gas tank for gas supply and vacuum tank for gas extraction needs to meet the operation of long duration, high speed and large wind port size, and the construction and operation cost is extremely high. It is appropriate to use the continuous gas supply and extraction mode of the unit. However, the gas supply unit and the gas extraction unit for ensuring the test operation are large and high-value equipment, so it is extremely difficult to adjust the working condition of the unit according to the requirements of test speed, pressure and flow rate, and it has a serious negative impact on the operation life of the unit, resulting in very high test cost and risk.

[0007] Therefore, it is urgent to develop an inlet dynamic test method that meets the requirement of continuous change of speed. SUMMARY

[0008] In order to solve the technical problems of high operation cost, high risk and large deviation of results caused by the traditional method which usually needs to go through the process of stopping gas, unsealing, adjusting the flow passage profile, sealing, gas supply and pressure regulation before a new speed flow field is obtained and then the test is carried out, the application discloses an inlet test method under continuous gas supply and extraction condition. The method carries out dynamic change of inlet characteristics test of the inlet under the condition of non-stop gas operation mode, and provides reliable test data support for the design and optimization of the inlet of advanced aircraft. The method comprises the following steps: Constructing a sub-model: based on the requirement of test speed change, constructing a sub-model of continuous adjustment of nozzle profile with speed, a sub-model of continuous adjustment of test device nozzle inlet and outlet pressure ratio with speed, and a sub-model of continuous adjustment of balance of gas supply and extraction pressure and flow rate with speed; generating variable speed regulation model: obtaining the dynamic change rule of target speed with time under the condition of non-stop air, inputting the dynamic change rule into each sub-model, combining the corresponding actuator control rule of each sub-model, and respectively establishing the variable speed regulation model of the change of the nozzle profile with time, the change of the test nozzle inlet and outlet pressure ratio with time, the balance of the supply and extraction air pressure and flow with time, and the change of the test piece attitude with time; Performing continuous variable speed blowing test: under the conditions of non-stop air and uninterrupted supply of extraction air, synchronously adjusting the flexible wall nozzle profile driving device, the main regulating valve group, the gas supply and extraction regulating valve group, and the attitude adjusting driving device through all the variable speed regulation models, so that the nozzle profile and the nozzle inlet and outlet pressure ratio change synchronously and coordinately, while the pressure and flow of the supply and extraction air are balanced, a continuous variable speed flow field with variable speed range and time is constructed, a test of continuously dynamically changing inlet velocity of the inlet of the inlet duct exceeding the local sound velocity is performed, and dynamic test data is synchronously collected.

[0009] Further, the sub-model of continuously adjusting the nozzle profile with speed is constructed, including: Based on the Laval nozzle flow passage throat area formula and the rule of the change of the nozzle profile with the outlet airflow velocity, the nozzle throat height and the height of each control point of the profile are obtained, a functional relationship of the change of the nozzle profile height with the Mach number is established, and is expressed as: ; Wherein, ht(Ma) is the curve function of the change of the nozzle throat height with the outlet airflow velocity, he is the nozzle outlet height, Ma is the outlet airflow velocity, k is the specific heat ratio of air, is the boundary layer correction coefficient of each control point along the nozzle axial direction after CFD simulation debugging correction.

[0010] Further, the sub-model of continuously adjusting the test nozzle inlet and outlet pressure ratio with speed is constructed, including: Based on the aerodynamic principle and the constraint condition of the supply and exhaust pressure regulation range of the test system, a functional relationship of the change of the ratio of the critical total pressure of the nozzle front stabilizing section to the nozzle outlet static pressure with the outlet airflow velocity is established, and is expressed as: ; Wherein, Ma is the outlet airflow velocity, π( Ma ) is the function of the ratio of the critical total pressure of the nozzle front stabilizing section to the nozzle outlet static pressure, is the critical total pressure of the nozzle front stabilizing section, P is the nozzle outlet static pressure, is the total pressure correction coefficient obtained after CFD simulation and debugging correction of the given nozzle system.

[0011] Further, a sub-model for maintaining the balance of the supply and extraction air pressure continuously adjusted with the speed is constructed, including: According to the valve system adjustment characteristics and the aerodynamic characteristics of the nozzle and the exhaust diffuser, the operation state of the supply air unit and the extraction air unit is maintained unchanged when the main flow rate changes by adjusting the intake adjustment valve group and the extraction adjustment valve group. The absolute value of the change of the vent valve flow rate due to the change of the main flow rate is equal to the absolute value of the change of the main flow rate, and the change direction is opposite, so that the test device supply end pressure and flow rate and the extraction end pressure and flow rate are basically maintained unchanged after the balance.

[0012] Further, a variable speed control model of the nozzle profile over time is established, 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 the speed, and simulation calculation is performed to obtain the displacement command of each actuator of the flexible wall nozzle profile driving device at each time, so as to obtain the variable speed control model of the nozzle profile over time.

[0013] Further, a variable speed control model of the test device nozzle inlet and outlet pressure ratio over time is established, including: The dynamic change law is input into the sub-model of the test device nozzle inlet and outlet pressure ratio continuously adjusted with the speed, and the ratio of the critical total pressure of the nozzle front stable section to the nozzle outlet static pressure at any time is calculated, so as to obtain the variable speed control model of the test device nozzle inlet and outlet pressure ratio over time, and the system boundary conditions include the supply air system boundary and the extraction air system boundary.

[0014] Further, a variable speed control model of the test device nozzle inlet and outlet pressure ratio over time is established, including: The dynamic change law and the control law of the valve system actuator are input into the sub-model of the supply and extraction air pressure balance continuously adjusted with the speed, and joint simulation is performed to obtain the opening change law of each adjustment valve when the main flow rate continuously changes and the supply air unit and the extraction air unit stably operate, so as to obtain the variable speed control model of each valve system over time under the premise of maintaining the balance of the supply and extraction air pressure and flow rate.

[0015] Further, a variable speed control model of the test device posture over time is established, including: The dynamic change law is input into the change law of the test device posture with the Mach number in the preset test working condition, and the angle and angular velocity control command of the test device posture adjusting mechanism in each degree of freedom over time is obtained according to the kinematics and dynamics control law of the posture adjusting mechanism, so as to obtain the variable speed control model of the test device posture over time.

[0016] Further, a test is conducted for the inlet velocity exceeding the local sound speed and continuously changing, including: The equipment is started and initial condition adjustment is completed, so that the test airflow velocity is stabilized in a given initial test nozzle outlet airflow velocity range; In the initial state, the control model parameters are input to each subsystem, the data acquisition system is started, and the dynamic characteristic test of continuously changing velocity is carried out, and the dynamic test data of the test velocity, the attitude angle, and the continuously changing internal geometric adjustment of the test piece are recorded synchronously; After the test is completed, the supply and extraction joint adjustment state is gradually exited, and the system operation is stopped.

[0017] The embodiment of the present application also provides a dynamic variable-speed inlet test system under continuous supply and extraction conditions for realizing the above method, and the system comprises an inlet regulating valve group, a diffuser section, a stable section, a convergent section, a flexible-wall nozzle, a test cabin, an inlet test piece, an attitude adjusting mechanism, an exhaust diffuser, and an extraction regulating valve group, the system adopts a front supply and rear extraction working mode, continuously dynamically adjusts the flexible-wall nozzle profile, continuously controls the nozzle inlet and outlet pressure ratio, and adjusts the flow of the vent valve group and the air supplement valve group, so that the dynamic test flow field of the inlet velocity exceeding the local sound speed and continuously changing is established; The flexible-wall nozzle is composed of flexible steel plates and is equipped with multiple groups of flexible-wall nozzle actuators, so that the remote continuous adjustment of the nozzle flow passage profile is realized under the condition of not stopping the air supply; The inlet regulating valve group adjusts the pressure and flow balance of the air supply end when the main flow changes, and the extraction regulating valve group adjusts the pressure and flow balance of the air extraction end when the main flow changes.

[0018] The method of the present application can make the inlet test velocity change correspond to the real flight condition of the aircraft, and the nozzle profile and nozzle pressure ratio adjustment speed and precision are matched with the test blowing speed change requirement; in order to reduce the operation risk and cost and protect the stable operation or slow-speed small-amplitude variable-condition operation of the large air compressor group of the test operation air supply and extraction, the test capacity of continuously changing the velocity exceeding the local sound speed under the continuous air supply and extraction conditions provides support for the dynamic performance design verification and optimization of the advanced aircraft inlet, and in general, the method has the following advantages: 1. The dynamic test of continuously changing the inlet velocity is realized, the air supply is not stopped, and the nozzle is replaced, and the test efficiency is significantly improved; 2. Through multi-parameter collaborative control, the large air supply and extraction group is protected to operate in a stable condition, and the equipment loss and operation cost are reduced; 3. The variable-speed flight condition of the aircraft is more realistically simulated, the dynamic performance parameters of the inlet are obtained, and the design verification precision is improved; 4. The long-time continuous test is supported, and the flow field characteristic research and instability characteristic analysis of high-risk flight tasks are suitable. Attached Figure Description

[0019] 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.

[0020] 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; 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. Figure 3 This is a schematic diagram of the test section; 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

[0021] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0022] 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.

[0023] 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: Building sub-models: based on the test speed variation requirements, a sub-model of continuously adjusting the nozzle profile with speed, a sub-model of continuously adjusting the test device nozzle inlet and outlet pressure ratio with speed, and a sub-model of continuously adjusting the balance of gas supply and extraction with speed are constructed; Generating variable speed control models: the dynamic variation law of target speed with time under the condition of non-stop gas is obtained, the dynamic variation law is input into each sub-model, and the corresponding execution mechanism control law of each sub-model is combined to respectively establish variable speed control models of nozzle profile change with time, test device nozzle inlet and outlet pressure ratio change with time, balance of gas supply and extraction change with time, and test piece attitude change with time. The execution mechanism includes a flexible wall nozzle execution mechanism, a test device main regulating valve system execution mechanism, a gas balance regulating valve system execution mechanism, an extraction balance regulating valve system execution mechanism, and a test piece attitude adjusting execution mechanism. The variable speed control model includes the control law and control target parameters of all execution mechanisms at each time sequence. Performing continuous variable speed blowing test: under the conditions of non-stop gas and uninterrupted gas supply and extraction, all the variable speed control models are used to synchronously adjust the flexible wall nozzle profile driving device, the main regulating valve group, the gas and extraction regulating valve group, and the attitude adjusting driving device, so that the nozzle profile and the nozzle inlet and outlet pressure ratio change synchronously and coordinately, while the pressure and flow balance of gas supply and extraction is maintained. A continuous variable speed flow field with variable speed range and time control is constructed, and a test of continuously and dynamically changing inlet velocity of the inlet of the inlet duct exceeding the local sound velocity is performed, and dynamic test data is synchronously collected.

[0024] Further, the sub-model of continuously adjusting the nozzle profile with speed is constructed, which includes: Based on the Laval nozzle flow passage throat area formula and the law of nozzle profile change with outlet airflow speed, the nozzle throat height and the height of each control point of the profile are obtained, and a function relationship of nozzle profile height change with Mach number is established, which is expressed as: ; Where ht(Ma) is the curve function of nozzle throat height change with outlet airflow speed, he is the nozzle outlet height, Ma is the outlet airflow speed, k is the specific heat ratio of air, is the boundary layer correction coefficient of each control point along the nozzle axial direction after CFD simulation debugging correction.

[0025] The Laval nozzle flow passage throat area formula is: ; In the above formula, is the flow function, which can be calculated by the nozzle outlet airflow speed and the specific heat ratio of air; Ma is the exit gas velocity, which is a dimensionless parameter relative to the local sound speed; is the curve of the nozzle throat height with Ma, which is obtained from theory, CFD simulation and commissioning correction; is the nozzle exit height; Meanwhile, according to the aerodynamic design, CFD checking and commissioning, the nozzle profile curve corresponding to the velocity Ma is: where x1,..., x n， is the displacement of the driving device push point of the nozzle profile corresponding to the velocity (Ma).

[0026] Further, a sub-model for continuously adjusting the test device nozzle inlet and outlet pressure ratio with the velocity is constructed, including: Based on the aerodynamic principle and the constraint conditions of the air supply and exhaust pressure adjustment range of the test system, the function relationship of the ratio of the critical total pressure of the nozzle front stable section to the nozzle exit static pressure with the exit gas velocity is established, which is expressed as: ; wherein, Ma is the exit gas velocity of the nozzle, π( Ma ) is the function of the ratio of the critical total pressure of the nozzle front stable section to the nozzle exit static pressure, is the critical total pressure of the nozzle front stable section, P is the nozzle exit static pressure, f (Ma) is the total static pressure ratio function under the corresponding exit gas velocity, is the total pressure correction coefficient of the given nozzle system obtained after CFD simulation and commissioning correction; The formula of aerodynamics principle is: .

[0027] Further, the variation of the vent valve flow caused by the variation of the main flow velocity is equal in absolute value to the variation of the main flow, and the variation of the main flow is equal in absolute value to the variation of the air supply valve flow, and the variation direction is opposite, so as to realize that the air supply end pressure and flow and the exhaust end pressure and flow of the test device remain basically unchanged after balance. Specifically, a sub-model for continuously adjusting the balance of the air supply and exhaust pressure with the velocity is constructed, including: According to the adjustment characteristics of the valve system and the aerodynamic characteristics of the nozzle and the exhaust diffuser, when the main flow changes, the operation state of the air supply unit and the exhaust unit is kept unchanged by adjusting the air inlet regulating valve group and the exhaust regulating valve group.

[0028] Further, the dynamic change rule of the target speed with time Ma(t) is achieved as a control model when the variable speed test is performed under the condition of no gas stop, and can be obtained according to the test variable speed requirement (variable speed range, time and variable speed rule), and belongs to the condition known before the test.

[0029] Further, the variable speed control model of the nozzle profile with time is established, including: The dynamic change rule and the control rule of the flexible wall nozzle actuator are input into the sub-model of the continuous adjustment of the nozzle profile with speed, the displacement instructions of each actuator in the flexible wall nozzle actuator at each time are obtained through simulation calculation, and the variable speed control model of the nozzle profile with time is obtained. Specifically, the variable speed control model of the nozzle profile with time is established by inputting Ma(t) of different time sequences into the model of the continuous adjustment of the nozzle profile with speed. .

[0030] Further, the variable speed control model of the test device nozzle inlet and outlet pressure ratio with time is established , including: The dynamic change rule is input into the sub-model of the continuous adjustment of the test device nozzle inlet and outlet pressure ratio with speed, the ratio of the critical total pressure of the nozzle front stable section to the nozzle outlet static pressure at any time is calculated, and the variable speed control model of the test device nozzle inlet and outlet pressure ratio with time is obtained, and the system boundary conditions include the gas supply system boundary and the gas extraction system boundary.

[0031] Further, the variable speed control model of the change of the balance of the gas supply and extraction pressure and flow with time is established , including: The dynamic change rule and the control rule of the valve system actuator are input into the sub-model of the continuous adjustment of the gas supply pressure balance with speed, and the change rule of the opening degree of each regulating valve in the process of continuous change of the main flow speed and flow is obtained through joint simulation to maintain stable operation of the gas supply unit and the gas extraction unit, and the variable speed control model of each valve system with time under the premise of maintaining the balance of the gas supply and extraction pressure and flow is obtained.

[0032] Further, the variable speed control model of the test piece attitude with time is established , , including: The dynamic change rule is input into the change rule of the test piece attitude with Mach number in the preset test working condition (including the change rule of the test piece attitude with Ma and ), the angle and angular velocity of the test piece attitude adjusting mechanism in each degree of freedom are obtained according to the kinematics and dynamics control rule of the attitude adjusting mechanism, and the variable speed control model of the test piece attitude with time is obtained.

[0033] 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.

[0034] Furthermore, tests were conducted where the inlet velocity of the air intake exceeded the local speed of sound and varied continuously, including: The equipment is started and initial operating condition is adjusted to stabilize the test airflow velocity within the given initial 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.

[0035] 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. 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. 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.

[0036] 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: 1. The dynamic test of continuously variable speed of the inlet channel is realized, without stopping the air supply and replacing the nozzle, and the test efficiency is significantly improved; 2. The multi-parameter collaborative control is used to ensure the operation of the large air supply and extraction unit in the stable working condition, and to reduce the equipment loss and operation cost; 3. The variable speed flight working condition of the aircraft is simulated more truly, the dynamic performance parameters of the inlet channel are obtained, and the design verification precision is improved; 4. The long-time continuous test is supported, and the flow field characteristic research and instability characteristic analysis of the high-risk flight task are applicable.

[0037] In the embodiment, a computer device is also provided, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor implements the dynamic variable speed inlet channel test method under the continuous air supply and extraction condition as described above when executing the computer program.

[0038] Specifically, the computer device can be a computer terminal, a server or a similar operation device.

[0039] In the embodiment, a computer readable storage medium is provided, which stores a computer program for executing the dynamic variable speed inlet channel test method under the continuous air supply and extraction condition as described above.

[0040] Specifically, the computer readable storage medium includes permanent and non-permanent, removable and non-removable media, which can be realized by any method or technology to store information. The 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 technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette tape, magnetic tape disk storage or other magnetic storage device, or any other non-transmission medium that can be used to store information accessible to a computing device. According to the definition in this paper, the computer readable storage medium does not include the transitory computer readable medium, such as modulated data signal and carrier wave.

[0041] 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.

[0042] 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 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.

2. The test method for dynamic variable speed intake under continuous air supply and extraction conditions according to claim 1, characterized in that, 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.

3. The test method for dynamic variable speed intake under continuous air supply and extraction conditions according to claim 1, characterized in that, 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 stable section before the nozzle and the static pressure at the nozzle exit, as a function of the exit airflow velocity. This relationship is 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 correction of a given nozzle system.

4. The test method for dynamic variable speed intake under continuous air supply and extraction conditions according to claim 1, characterized in that, 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.

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 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.

6. 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.

7. 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.

8. 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.

9. 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.

10. A dynamic variable speed inlet test system for implementing the method as described in any one of claims 1-9 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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