Variable Mach wind tunnel control method

Abstract

The invention provides a variable Mach wind tunnel control method, which is applied to a variable Mach wind tunnel comprising a combustion warmer and a variable Mach spray pipe, and comprises the following steps: firstly, detecting a test environment establishment condition, obtaining test demand data comprising a plurality of target working conditions and parameters thereof, and a required steady-state or dynamic test mode, and in the steady-state test mode, establishing a variable Mach wind tunnel; the method comprises the following steps: judging the instability condition of a flow field, planning a path from the current to a to-be-switched working condition, and controlling a variable Mach nozzle and a combustion warmer to execute corresponding actions, so as to realize stable switching, in a dynamic test mode, subdividing the switching path into a plurality of discrete working conditions by adopting a discrete segmentation method, and completing working condition switching by gradually approaching each discrete working condition. The overall control logic of the operation method of the combustion warmer and the variable Mach nozzle is taken into consideration, and the rapid flexibility and the continuous adjustment capability of the wind tunnel in the test are improved.

Description

Technical Field

[0001] This application relates to the technical field of wind tunnel control, and particularly to a variable Mach wind tunnel control method. Background Art

[0002] In recent years, supersonic wind tunnel technology has been widely used to simulate the high-altitude flight environment of aircraft, including key parameters such as flight Mach number, altitude, and total flight temperature. Traditional supersonic wind tunnels can usually only simulate a fixed flight environment, while variable Mach wind tunnels can simulate a continuously changing flight environment under a real flight trajectory, including dynamic parameters such as Mach number, flight altitude (static pressure), and total flight temperature, thereby providing test conditions closer to actual flight.

[0003] A typical variable Mach wind tunnel includes a combustion heater and a variable Mach nozzle. The combustion heater provides gas with the required temperature, pressure, and flow rate by controlling the ratio of combustion, oxidizer, and coolant to simulate the total flight pressure and total temperature, mainly using a phased time-sequence open-loop control method. The variable Mach nozzle converts the gas at the outlet of the combustion heater into a continuously changing flow field through continuous changes to simulate the flight Mach number and flight altitude, mainly using a continuous feedback closed-loop control method. However, the current control methods have limitations. For example, the phased time-sequence open-loop control method cannot give the required parameters in real time, affecting the test flexibility, while the continuous feedback closed-loop control method may cause the combustion heater to fail to follow the nozzle state synchronously, resulting in test failure. Therefore, there is an urgent need to develop an overall control logic that can take into account the operation methods of both the combustion heater and the variable Mach nozzle to improve the rapid flexibility and continuous adjustment ability of the wind tunnel during tests, while ensuring the reliability and safety of wind tunnel operation. Summary of the Invention

[0004] An embodiment of this application provides a variable Mach wind tunnel control method.

[0005] According to the first aspect of this application, there is provided a variable Mach wind tunnel control method applied to the main control system of a variable Mach wind tunnel. The variable Mach wind tunnel further includes a combustion heater and a variable Mach nozzle. The method includes:

[0006] When it is detected that the test environment is established, obtain test requirement data. The test requirement data includes a test environment group and a test mode. The test environment group includes a plurality of target working conditions and the working condition parameters of each target working condition. The test mode includes a steady-state test mode and a dynamic test mode;

[0007] When the test mode is the steady-state test mode, control the variable Mach wind tunnel to simulate and test the flight environment corresponding to each target operating condition based on the steady-state operating condition switching mechanism, the multiple target operating conditions, and the operating condition parameters of each target operating condition; the steady-state operating condition switching mechanism includes: judging the flow field instability according to the operating condition parameters of the current operating condition and the operating condition to be switched; determining the switching path between the current operating condition and the operating condition to be switched according to the flow field instability judgment result; controlling the variable Mach nozzle and the combustion heater to execute actions corresponding to the switching path to control the variable Mach wind tunnel to switch from the current operating condition to the operating condition to be switched;

[0008] When the test mode is the dynamic test mode, control the variable Mach wind tunnel to simulate and test the flight environment corresponding to each target operating condition based on the dynamic operating condition switching mechanism, the multiple target operating conditions, and the operating condition parameters of each target operating condition; the dynamic operating condition switching mechanism includes: discretizing the switching path between the current operating condition and the operating condition to be switched into multiple discrete operating conditions according to the discrete segmentation method and the operating condition parameters of the current operating condition and the operating condition to be switched; controlling the variable Mach nozzle and the combustion heater to execute actions corresponding to the multiple discrete operating conditions to control the variable Mach wind tunnel to switch from the current operating condition to the operating condition to be switched.

[0009] According to an embodiment of the present application, the determining the switching path between the current operating condition and the operating condition to be switched according to the flow field instability judgment result includes:

[0010] If the flow field is not unstable, construct a switching path including the current operating condition and the operating condition to be switched;

[0011] If the flow field is unstable, use the equal-spacing segmentation method to segment the path between the current operating condition and the operating condition to be switched until the flow field is stable, obtain at least one transition operating condition obtained by segmentation, and construct a switching path including the current operating condition, at least one transition operating condition, and the operating condition to be switched.

[0012] According to an embodiment of the present application, the controlling the variable Mach nozzle and the combustion heater to execute actions corresponding to the switching path includes:

[0013] Obtain the operating condition parameters of each operating condition within the switching path;

[0014] According to the operating condition parameters of each operating condition within the switching path and the execution priority mechanism, control the combustion heater and the variable Mach nozzle to sequentially execute actions corresponding to each operating condition until the current operating condition is switched to the operating condition to be switched;

[0015] Among them, the execution priority mechanism includes: according to the working condition parameters of each working condition, comparing the total incoming flow pressure and total incoming flow temperature of the current working condition and the switching working condition to which the current working condition needs to be switched, and comparing the switching time of the combustion heater and the switching time of the variable Mach nozzle to obtain a total pressure comparison result, a total temperature comparison result, and a switching time comparison result; determining the start priority and start time of the combustion heater and the variable Mach nozzle according to the total pressure comparison result, the total temperature comparison result, the switching time comparison result, and the system synchronization mechanism; and controlling the combustion heater and the variable Mach nozzle to perform corresponding actions according to the start priority and start time of the combustion heater and the variable Mach nozzle and the working condition parameters of the current working condition and the switching working condition to which the current working condition needs to be switched.

[0016] According to an embodiment of the present application, the working condition parameters include Mach number; correspondingly,

[0017] Discretizing the switching path between the current working condition and the to-be-switched working condition into a plurality of discrete working conditions according to the discrete segmentation method and the working condition parameters of the current working condition and the to-be-switched working condition includes:

[0018] Determining the number of discretizations according to the Mach numbers of the current working condition and the to-be-switched working condition;

[0019] Discretizing the path between the current working condition and the to-be-switched working condition into a plurality of discrete working conditions corresponding to the number of discretizations according to the number of discretizations.

[0020] According to an embodiment of the present application, controlling the variable Mach nozzle and the combustion heater to perform actions corresponding to a plurality of discrete working conditions includes:

[0021] Obtaining the working condition parameters of each discrete working condition;

[0022] Controlling the combustion heater and the variable Mach nozzle to sequentially perform actions corresponding to each discrete working condition simultaneously according to the working condition parameters of each discrete working condition until the current working condition is switched to the to-be-switched working condition.

[0023] According to an embodiment of the present application, the variable Mach wind tunnel further includes a low-pressure exhaust system, a high-altitude test chamber, a test piece placed in the high-altitude test chamber, and a cooling system for the variable Mach nozzle, the combustion heater, the low-pressure exhaust system, and the high-altitude test chamber; correspondingly,

[0024] Detecting that the test environment is established through the following operations:

[0025] Controlling the variable Mach nozzle to move the nozzle to a preset nozzle initial position;

[0026] Controlling the combustion heater to move the regulating valve to a preset valve initial position;

[0027] Start all cooling systems;

[0028] Receive an initial power - on signal, and in response to the initial power - on signal, perform a power - on operation according to the set power - on logic;

[0029] When it is detected that the power - on operation is completed, determine that the test environment is established;

[0030] Wherein, the set power - on logic includes: controlling the low - pressure exhaust system to power on; when it is monitored that the pressure in the high - altitude test chamber is in a stable state, controlling the combustion heater to power on, and when no power - on failure signal is received from the combustion heater within a set time period, determine that the power - on operation is completed.

[0031] According to an embodiment of the present application, the method further includes:

[0032] When it is detected that the test is completed, control the combustion heater and the variable Mach nozzle to shut down according to the set shutdown logic;

[0033] Wherein, the set shutdown logic includes: sending a shutdown signal to the combustion heater and the variable Mach nozzle, so that the variable Mach nozzle and the combustion heater respond to the shutdown signal to shut down; when the combustion heater has completed shutdown, control the combustion heater to perform nitrogen purging and air purging; when the purging is completed, send a shutdown signal to all cooling systems and send a nozzle return signal to the variable Mach nozzle, so that all cooling systems respond to the shutdown signal to shut down, and the variable Mach nozzle responds to the initial return signal to move the nozzle to a preset initial nozzle position.

[0034] According to an embodiment of the present application, the controlling the combustion heater to perform nitrogen purging and air purging includes:

[0035] Send a nitrogen purging signal to the combustion heater, so that the combustion heater responds to the nitrogen purging signal to start nitrogen purging;

[0036] When the nitrogen purging is completed, send a shutdown signal to the low - pressure exhaust system, so that the low - pressure exhaust system responds to the shutdown signal to shut down;

[0037] When the low - pressure exhaust system has completed shutdown, send an air purging signal to the combustion heater, so that the combustion heater responds to the air purging signal to perform air purging.

[0038] According to an embodiment of the present application, the method further includes:

[0039] Upon receiving a cooling emergency stop signal, send a shutdown signal to the combustion heater and the variable Mach nozzle so that the variable Mach nozzle and the combustion heater respond to the shutdown signal and shut down;

[0040] Upon completion of the shutdown of the variable Mach nozzle and the combustion heater, detect the faulty cooling system that triggered the cooling emergency stop signal and send a shutdown signal to the faulty cooling system;

[0041] Upon completion of the shutdown of the faulty cooling system, send a shutdown signal to the low-pressure exhaust system so that the low-pressure exhaust system responds to the shutdown signal and shuts down;

[0042] Upon completion of the shutdown of the low-pressure exhaust system, send a shutdown signal to other cooling systems.

[0043] According to an embodiment of the present application, the variable Mach wind tunnel further includes a fault system; correspondingly,

[0044] The method further includes:

[0045] Receive a fault emergency stop signal sent by the fault system when a fault is detected;

[0046] Send a shutdown signal to the combustion heater and the variable Mach nozzle so that the variable Mach nozzle and the combustion heater respond to the shutdown signal and shut down;

[0047] Upon completion of the shutdown of the variable Mach nozzle and the combustion heater, send a shutdown signal to the low-pressure exhaust system so that the low-pressure exhaust system responds to the shutdown signal and shuts down;

[0048] Upon completion of the shutdown of the low-pressure exhaust system, send a shutdown signal to all cooling systems.

[0049] A variable Mach wind tunnel control method according to an embodiment of the present application first detects the establishment of the test environment, obtains test requirement data including multiple target working conditions and their parameters, and the required steady-state or dynamic test mode. In the steady-state test mode, by judging the instability of the flow field, plan the path from the current to the to-be-switched working condition, and control the variable Mach nozzle and the combustion heater to perform corresponding actions to achieve a smooth switch. In the dynamic test mode, use the discrete segmentation method to divide the switching path into multiple discrete working conditions, and complete the working condition conversion by gradually approaching each discrete working condition. It realizes the overall control logic of the operation methods of the combustion heater and the variable Mach nozzle, and improves the fast flexibility and continuous adjustment ability of the wind tunnel during the test.

[0050] It should be understood that the teachings of the present application do not necessarily achieve all the beneficial effects described above. Instead, specific technical solutions can achieve specific technical effects, and other embodiments of the present application can also achieve beneficial effects not mentioned above. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] By referring to the following detailed description with reference to the accompanying drawings, the above and other objects, features, and advantages of the exemplary embodiments of the present application will become readily understood. In the drawings, several embodiments of the present application are shown in an exemplary rather than restrictive manner, where:

[0052] In the drawings, the same or corresponding reference numerals represent the same or corresponding parts.

[0053] Figure 1 FIG. shows a schematic structural diagram of the composition of a variable Mach wind tunnel provided by an embodiment of the present application;

[0054] Figure 2 FIG. shows a schematic implementation flow diagram of a method for controlling a variable Mach wind tunnel provided by an embodiment of the present application;

[0055] Figure 3 FIG. shows a schematic implementation flow diagram of a path switching operation of a method for controlling a variable Mach wind tunnel provided by an embodiment of the present application;

[0056] Figure 4 FIG. shows a schematic implementation flow diagram of a startup operation of a method for controlling a variable Mach wind tunnel provided by an embodiment of the present application;

[0057] Figure 5 FIG. shows a schematic implementation flow diagram of a cooling emergency stop operation of a method for controlling a variable Mach wind tunnel provided by an embodiment of the present application;

[0058] Figure 6 FIG. shows a schematic implementation flow diagram of a fault emergency stop operation of a method for controlling a variable Mach wind tunnel provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0059] To make the objectives, features, and advantages of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present application.

[0060] Figure 1 FIG. shows a schematic structural diagram of the composition of a variable Mach wind tunnel provided by an embodiment of the present application.

[0061] Reference Figure 1, this application provides a variable Mach wind tunnel. The variable Mach wind tunnel includes multiple core modules such as a main control system, a combustion heater, a variable Mach nozzle, a high-altitude test chamber (including test pieces), and a low-pressure exhaust system, and also includes a cooling system for the combustion heater, the variable Mach nozzle, the high-altitude test chamber, and the low-pressure exhaust system. Among them, the variable Mach wind tunnel control method of the embodiments of this application is applied to the main control system of the variable Mach wind tunnel. The main control system is connected to the combustion heater, the variable Mach nozzle, the high-altitude test chamber, the low-pressure exhaust system, and all cooling systems, and can realize the control of each part and the communication with each part.

[0062] Figure 2 The figure shows a schematic implementation flow diagram of the variable Mach wind tunnel control method provided by the embodiments of this application.

[0063] Reference Figure 2 , the embodiments of this application provide a variable Mach wind tunnel control method, which is applied to the main control system of the variable Mach wind tunnel including the above Figure 1 , and the method includes:

[0064] Operation 101, when it is detected that the test environment is established, obtain test requirement data. The test requirement data includes a test environment group and a test mode. The test environment group includes multiple target working conditions and the working condition parameters of each target working condition. The test mode includes a steady-state test mode and a dynamic test mode.

[0065] Before the test needs to be carried out, the test environment needs to be established in advance. When the test environment is established, obtain the test requirement data required for the test, and start the test.

[0066] Among them, the test requirement data includes a test environment group and a test mode. The test usually refers to testing the state of the test piece in various flight environments. The flight environment is simulated based on the working conditions. Therefore, when conducting the test, it is necessary to obtain a test environment group including multiple target working conditions. Each target working condition can be regarded as the simulation of a flight environment. Switching the working condition can be regarded as a change in the working condition parameters. Therefore, in order to realize the switching between target working conditions, it is also necessary to obtain the working condition parameters of each target working condition.

[0067] In an embodiment of this application, the working condition parameters are configured in advance by the test operator or calculated by the main control system according to the environmental parameters and the characteristics of the variable Mach nozzle and the combustion heater. The working condition parameters may include but are not limited to Mach number, altitude, total temperature, total pressure, the flow rate, temperature, and the corresponding position of the regulating valve output by the combustion heater, and the nozzle position of the variable Mach nozzle.

[0068] When the test only requires multiple fixed flight environments, the states during the switching of each flight environment do not need to be considered. In this case, the wind tunnel can complete the switching of working conditions as soon as possible on the premise of a stable flow field. When the test not only requires multiple flight environments but also needs to simulate a dynamic flight environment, it is necessary to ensure the continuity of the working condition switching state and the environmental matching of flight speed and altitude. Therefore, the embodiment of the present application is also configured with test modes, adopting a steady-state test mode to adapt to the scenario that only requires fixed flight environments, and adopting a dynamic test mode to adapt to the scenario that needs to simulate a dynamic flight environment.

[0069] Before the test is required, the test mode that needs to be tested currently has been configured. Therefore, it can be obtained when the test needs to be carried out.

[0070] Operation 102, when the test mode is the steady-state test mode, control the variable Mach number wind tunnel to simulate and test the flight environment corresponding to each target working condition based on multiple target working conditions and the working condition parameters of each target working condition according to the steady-state working condition switching mechanism; the steady-state working condition switching mechanism includes: judging the instability of the flow field according to the working condition parameters of the current working condition and the to-be-switched working condition; determining the switching path between the current working condition and the to-be-switched working condition according to the flow field instability judgment result; controlling the variable Mach number nozzle and the combustion heater to execute actions corresponding to the switching path to control the variable Mach number wind tunnel to switch from the current working condition to the to-be-switched working condition.

[0071] The main difference between the steady-state test mode and the dynamic test mode lies in the switching process of the working conditions. The steady-state test mode does not need to consider the dynamic stability of the flight environment. Therefore, when switching the working conditions, the fastest working condition switching can be achieved under the condition of ensuring that the flow field does not become unstable.

[0072] To implement the steady-state test mode, a steady-state working condition switching mechanism is configured for its working condition conversion. The main purpose of the steady-state working condition switching mechanism is to determine the switching path under a stable flow field, specifically including determining whether a direct switch between the current working condition and its to-be-switched working condition can ensure the stability of the flow field, and then determining the switching path according to the flow field stability judgment result and the working condition parameters of the current working condition and the to-be-switched working condition.

[0073] In an embodiment of the present application, determining the switching path between the current working condition and the to-be-switched working condition according to the flow field instability judgment result includes: if the flow field is not unstable, constructing a switching path including the current working condition and the to-be-switched working condition; if the flow field is unstable, using the equal-spacing slicing method to slice the path between the current working condition and the to-be-switched working condition until the flow field is stable, obtaining at least one intermediate working condition obtained by slicing, and constructing a switching path including the current working condition, at least one intermediate working condition and the to-be-switched working condition.

[0074] If direct switching can ensure the stability of the flow field, then directly switching the current working condition to the to-be-switched working condition is determined as an implementable switching path. If direct switching cannot ensure the stability of the flow field, then the path from the current working condition to the to-be-switched working condition needs to be segmented until the flow field is stable. Among them, the path segmentation can adopt the equal-spacing segmentation method, which can be regarded as segmenting multiple equally spaced transition working conditions between the current working condition and the to-be-switched working condition. The specific process of path segmentation is as follows: If it is calculated that the flow field instability problem will occur, an intermediate working condition is automatically set, and the intermediate working condition is set as the new end working condition (to-be-switched working condition), and then the flow field instability judgment is carried out and the above process of setting the intermediate working condition is repeated until the instability problem no longer appears. Accordingly, the main control system converts the switching path from the current working condition to the to-be-switched working condition into a switching path including several stable transition working conditions.

[0075] In an embodiment of the present application, the stability of the flow field can be judged by the following formula:

[0076]

[0077] Wherein, T 0 represents the total temperature, P 0 represents the total pressure, γ represents the specific heat ratio of the air flow, Ma represents the Mach number, and P s represents the pressure in the test chamber. The total temperature, total pressure, and Mach number can all be calculated in real time by the main control system when needed and are included in the working condition parameters. The pressure in the test chamber can be obtained based on the monitoring of the high-altitude test chamber by the main control system.

[0078] After determining the final transition working condition, by controlling the combustion heater and the variable Mach nozzle to gradually execute the actions corresponding to the working condition parameters of the corresponding working condition according to the working condition sequence. Among them, the action of the combustion heater can be regarded as adjusting the position of its regulating valve, and the action of the variable Mach nozzle can be regarded as moving the position of the nozzle.

[0079] Among them, when all the working conditions of the switching path have been switched, the variable Mach nozzle and the combustion heater will feedback the signal of completing the switching. At this time, the main control system judges that the working condition switching is completed.

[0080] Operation 103, in the case that the test mode is the dynamic test mode, control the variable Mach wind tunnel to simulate and test the flight environment corresponding to each target working condition based on multiple target working conditions and the working condition parameters of each target working condition; the dynamic working condition switching mechanism includes: according to the discrete segmentation method and the working condition parameters of the current working condition and the to-be-switched working condition, segment the switching path between the current working condition and the to-be-switched working condition into multiple discrete working conditions; control the variable Mach nozzle and the combustion heater to execute the actions corresponding to the multiple discrete working conditions to control the variable Mach wind tunnel to switch from the current working condition to the to-be-switched working condition.

[0081] In the dynamic test mode, it is necessary to consider the dynamic state during the flight environment switch to ensure the continuous adjustment of the combustion heater. Therefore, a dynamic working condition switching mechanism is configured for the dynamic test mode. The main purpose of the dynamic working condition switching mechanism is to divide the switch between two working conditions into the switches of multiple adjacent working conditions (discrete working conditions) through the method of discrete segmentation.

[0082] In an embodiment of the present application, the working condition parameters include Mach number; correspondingly, according to the discrete segmentation method and the working condition parameters of the current working condition and the to-be-switched working condition, the switching path between the current working condition and the to-be-switched working condition is discretized into multiple discrete working conditions, including: determining the discrete number according to the Mach numbers of the current working condition and the to-be-switched working condition; and discretizing the path between the current working condition and the to-be-switched working condition into multiple discrete working conditions corresponding to the discrete number according to the discrete number.

[0083] The working condition parameters may specifically include Mach number, altitude, total temperature, and total pressure. The process of discretizing multiple discrete working conditions may include: calculating the discrete number n according to the Mach number, and dividing the Mach number, altitude, total temperature, and total pressure between the current working condition and the to-be-switched working condition into n equal parts to obtain n discrete working conditions and corresponding working condition parameters.

[0084] In an embodiment of the present application, the discrete number can be calculated by the following formula:

[0085]

[0086] where n represents the discrete number, Ma 1 represents the Mach number of the current working condition, and Ma 2 represents the Mach number of the to-be-switched working condition.

[0087] For example, assume that the Mach number Ma 1 and the working condition altitude H 1 of the starting working condition (current working condition), and the Mach number Ma 2 and the working condition altitude H 2 of the ending working condition (to-be-switched working condition). The discrete number can be calculated as: After that, the altitude is divided into H 1 ~H n , the corresponding total temperature is divided into T0 1 ~T0 n , and the total pressure is divided into P0 1 ~P0 n . Finally, the above dynamic switching process is converted into n discrete working conditions, and each discrete working condition includes corresponding working condition parameters such as Mach number, altitude, total temperature, and total pressure.

[0088] In an embodiment of the present application, the control variable Mach nozzle and the combustion heater are controlled to perform actions corresponding to multiple discrete operating conditions, including: obtaining the operating condition parameters of each discrete operating condition; according to the operating condition parameters of each discrete operating condition, controlling the combustion heater and the variable Mach nozzle to sequentially perform actions corresponding to each discrete operating condition simultaneously until the current operating condition is switched to the to-be-switched operating condition.

[0089] After determining each discrete operating condition, the combustion heater and the variable Mach nozzle are further controlled to perform corresponding actions according to the switching sequence of the discrete operating conditions based on the operating condition parameters of the discrete operating conditions. Among them, when it is necessary to switch discrete operating conditions, the operating condition parameters of each discrete operating condition are expanded by the main control system according to the Mach number, altitude, total temperature, and total pressure to include the output flow rate, temperature, and regulating valve position of the combustion heater and the nozzle position of the variable Mach nozzle. In this way, when performing the discrete operating condition switching, the combustion heater and the variable Mach nozzle perform corresponding actions according to the expanded operating condition parameters to complete the operating condition switching.

[0090] In an embodiment of the present application, in each discrete operating condition, the action execution of the combustion heater and the variable Mach nozzle includes: in each discrete operating condition, when the main control system receives the end signal of the previous discrete operating condition, it simultaneously issues an operating condition switching signal and a discrete switching target to the combustion heater and the variable Mach nozzle and starts timing. The combustion heater and the variable Mach nozzle act on their own according to the switching target. Among them, the combustion heater does not feedback a completion signal to the main control system during the switching, and the variable Mach nozzle feedbacks a completion signal to the main control system after the switching is completed. When the main control system receives the signal and the timing exceeds 0.8 s, it sends the end signal of the current discrete operating condition switching and starts the switching of the next discrete operating condition. Among them, the switching target is the operating condition parameter of the expanded discrete operating condition.

[0091] In this way, the solution of the embodiment of the present application first detects the establishment of the test environment, obtains the test requirement data including multiple target operating conditions and their parameters, and the required steady-state or dynamic test modes. In the steady-state test mode, by judging the instability of the flow field, the path from the current operating condition to the to-be-switched operating condition is planned, and the variable Mach nozzle and the combustion heater are controlled to perform corresponding actions to achieve a smooth switch. In the dynamic test mode, the discrete segmentation method is used to divide the switching path into multiple discrete operating conditions, and the operating condition conversion is completed by gradually approaching each discrete operating condition. It realizes the overall control logic of the operation methods of the combustion heater and the variable Mach nozzle, improves the fast flexibility and continuous adjustment ability of the variable Mach wind tunnel in the test, ensures that the variable Mach wind tunnel can quickly and flexibly continuously adjust the test environment in the test state, accurately matches the flight Mach number and flight altitude environment, and at the same time ensures that the variable Mach wind tunnel can respond to immediate needs to replace the Mach number and flight environment. It also realizes the autonomous selection of the steady-state test and the dynamic test by the variable Mach wind tunnel.

[0092] Figure 3The figure shows a schematic diagram of the implementation process of the path switching operation of the variable Mach number wind tunnel control method provided by the embodiments of the present application.

[0093] Referring to Figure 3 , in an embodiment of the present application, controlling the variable Mach number nozzle and the combustion heater to perform actions corresponding to the switching path includes: operation 201, obtaining the condition parameters of each condition in the switching path; operation 202, according to the condition parameters of each condition in the switching path and the execution priority mechanism, controlling the combustion heater and the variable Mach number nozzle to sequentially perform actions corresponding to each condition until the current condition is switched to the to-be-switched condition; wherein, the execution priority mechanism includes: according to the condition parameters of each condition, comparing the total incoming flow pressure and the total incoming flow temperature of the current condition and the switching condition to which the current condition needs to be switched, and comparing the switching time of the combustion heater and the switching time of the variable Mach number nozzle to obtain a total pressure comparison result, a total temperature comparison result, and a switching time comparison result; according to the total pressure comparison result, the total temperature comparison result, the switching time comparison result, and the system synchronization mechanism, determining the start priority and start time of the combustion heater and the variable Mach number nozzle; and controlling the combustion heater and the variable Mach number nozzle to perform corresponding actions according to the start priority and start time of the combustion heater and the variable Mach number nozzle and the condition parameters of the current condition and the switching condition to which the current condition needs to be switched.

[0094] When performing condition switching in the steady-state test mode, in order to ensure the coordination between the variable Mach number nozzle and the combustion heater, it is also necessary to determine the execution priority and start time of the variable Mach number nozzle and the combustion heater, so that the variable Mach number nozzle and the combustion heater can cooperate with each other when performing condition switching. To achieve the above coordination, the embodiments of the present application configure an execution priority mechanism to determine the execution priority and start time of the variable Mach number nozzle and the combustion heater through the execution priority mechanism, and control the variable Mach number nozzle and the combustion heater to perform corresponding actions.

[0095] The purpose of the execution priority mechanism is mainly to determine which of the variable Mach number nozzle and the combustion heater starts first for each condition switching. The purpose of the system synchronization mechanism is to ensure that the end times of the combustion heater and the variable Mach number nozzle are maintained as synchronized as possible when switching conditions each time. The execution priority mechanism specifically includes: comparing the total incoming flow pressure and total temperature shown in the condition parameters of the current condition and the to-be-switched condition, and comparing the switching time taken by the combustion heater and the variable Mach number nozzle to switch from the current condition to the to-be-switched condition to obtain a total pressure comparison result, a total temperature comparison result, and a switching time comparison result. Finally, according to the total pressure comparison result, the total temperature comparison result, the switching time comparison result, and the system synchronization mechanism, determining the start priority and start time of the combustion heater and the variable Mach number nozzle, and controlling the combustion heater and the variable Mach number nozzle to perform corresponding actions.

[0096] In an embodiment of the present application, according to the total pressure ratio comparison result, the total temperature ratio comparison result, the switching time comparison result, and the system synchronization mechanism, the startup priorities and startup times of the combustion heater and the variable Mach nozzle are determined, including:

[0097] When the total pressure ratio comparison result and the total temperature ratio comparison result indicate an increase in the incoming flow total pressure or total temperature, if the switching time comparison result shows that the switching time of the combustion heater is less than the switching time of the variable Mach nozzle, the main control system first issues a startup signal for the variable Mach nozzle to control the variable Mach nozzle to start preferentially, and then calculates the startup time of the combustion heater by back-calculating from the time point when the variable Mach nozzle completes the switching, and issues a startup signal for the combustion heater at this startup time point to control the combustion heater to start;

[0098] When the total pressure ratio comparison result and the total temperature ratio comparison result indicate an increase in the incoming flow total pressure or total temperature, if the switching time comparison result shows that the switching time of the combustion heater is greater than the switching time of the variable Mach nozzle, the main control system issues startup signals for the variable Mach nozzle and the combustion heater simultaneously to control the variable Mach nozzle and the combustion heater to start simultaneously;

[0099] When the total pressure ratio comparison result and the total temperature ratio comparison result indicate a decrease in the incoming flow total pressure or total temperature, if the switching time comparison result shows that the switching time of the combustion heater is less than the switching time of the variable Mach nozzle, the main control system issues startup signals for the variable Mach nozzle and the combustion heater simultaneously to control the variable Mach nozzle and the combustion heater to start simultaneously;

[0100] When the total pressure ratio comparison result and the total temperature ratio comparison result indicate a decrease in the incoming flow total pressure or total temperature, if the switching time comparison result shows that the switching time of the combustion heater is greater than the switching time of the variable Mach nozzle, the main control system first issues a startup signal for the combustion heater to control the combustion heater to start, and then calculates the startup time of the variable Mach nozzle by back-calculating from the time point when the combustion heater completes the switching, and issues a startup signal for the variable Mach nozzle at this startup time point to control the variable Mach nozzle to start.

[0101] Figure 4 The figure shows a schematic diagram of the implementation process of the startup operation of the variable Mach wind tunnel control method provided by the embodiment of the present application.

[0102] Refer to Figure 4 In an embodiment of the present application, refer to Figure 1 The variable Mach wind tunnel includes a low-pressure exhaust system, a high-altitude test chamber, a test piece placed in the high-altitude test chamber, and a variable Mach nozzle, a combustion heater, and a cooling system for the low-pressure exhaust system and the high-altitude test chamber. The establishment of the test environment for the above operation 101 can be detected through the following operations:

[0103] Operation 301: Control the variable Mach nozzle to move the nozzle to a preset initial nozzle position;

[0104] Operation 302, controlling the combustion heater to move the regulating valve to the preset initial valve position;

[0105] Operation 303, starting all cooling systems;

[0106] Operation 304, receiving an initial startup signal, and in response to the initial startup signal, performing a startup operation according to the set startup logic;

[0107] Operation 305, when it is detected that the startup operation is completed, determining that the test environment is established; wherein, the set startup logic includes: controlling the low-pressure exhaust system to start up; when it is monitored that the pressure in the high-altitude test chamber is in a stable state, controlling the combustion heater to start up, and when no startup failure signal is received from the combustion heater within a set time period, determining that the startup operation is completed.

[0108] In addition to the test process, in order to achieve the main control of the variable Mach wind tunnel, there are also configured control methods for the normal startup, normal shutdown, cooling emergency stop, and fault emergency stop of the variable Mach wind tunnel.

[0109] When the test environment is established, it can be regarded as the startup being completed. The startup control process is specifically as follows: Before startup, the main control system controls the variable Mach nozzle to move to the preset initial nozzle position (the position corresponding to the preset initial Mach number), and controls the regulating valve of the combustion heater to move to the preset initial valve position (the corresponding position required for the preset initial flight environment), and then starts the cooling system. After receiving the initial startup signal, control the low-pressure exhaust system to start up. When it is detected that the pressure in the high-altitude test chamber is stable, record the pressure P in the high-altitude test chamber s , and send a startup completion signal. 2 s after sending the startup completion signal, the main control system sends a startup signal to the combustion heater, and when no startup failure signal is received from the combustion heater, after timing for 6 s, mark that the test environment is established and the test can be carried out.

[0110] In an embodiment of the present application, a control method for the normal shutdown of the variable Mach wind tunnel is further provided, which specifically includes: when it is detected that the test is completed, controlling the combustion heater and the variable Mach nozzle to shut down according to the set shutdown logic; wherein, the set shutdown logic includes: sending a shutdown signal to the combustion heater and the variable Mach nozzle, so that the variable Mach nozzle and the combustion heater respond to the shutdown signal to shut down; when the combustion heater has completed shutting down, controlling the combustion heater to perform nitrogen purging and air purging; when the purging is completed, sending a shutdown signal to all cooling systems and sending a nozzle return signal to the variable Mach nozzle, so that the cooling systems respond to the shutdown signal to shut down, and the variable Mach nozzle responds to the initial return signal to move the nozzle to the preset initial nozzle position.

[0111] In an embodiment of the present application, controlling the combustion heater to perform nitrogen purging and air purging includes: sending a nitrogen purging signal to the combustion heater to cause the combustion heater to start nitrogen purging in response to the nitrogen purging signal; when the nitrogen purging is completed, sending a shutdown signal to the low-pressure exhaust system to cause the low-pressure exhaust system to shut down in response to the shutdown signal; when the shutdown of the low-pressure exhaust system is completed, sending an air purging signal to the combustion heater to cause the combustion heater to perform air purging in response to the air purging signal.

[0112] Specifically, the entire control process for normal shutdown is as follows: After the test is completed, the main control system sends shutdown signals to the combustion heater and the variable Mach nozzle. After receiving the shutdown signal, the variable Mach nozzle directly stops actuating and maintains its position regardless of its current state. After receiving the shutdown signal, the combustion heater shuts down according to the normal process (disconnecting the fuel supply and the combustion promoter supply). After the shutdown is completed, it sends a shutdown completion signal to the main control system and simultaneously starts nitrogen purging for more than 20 s to blow out the fuel remaining in the gaps between the combustion heater and the variable Mach nozzle. After the nitrogen purging is completed, it sends a completion signal to the main control system. After receiving this signal, the main control system sends a shutdown signal to the low-pressure exhaust system. After receiving the signal, the low-pressure exhaust system starts to shut down according to the slow shutdown process and sends a completion signal after the shutdown is completed. After receiving this signal, the main control system sends an air purging signal to the combustion heater, and the combustion heater starts air purging to cool down the entire wind tunnel.

[0113] Among them, the purging time of the air purging is judged by the main control system according to the maximum total temperature (included in the operating condition parameters). When the maximum total temperature reaches above 1600 K, the purging time is not less than 90 s; when the maximum total temperature reaches above 1300 K, the purging time is not less than 60 s; when the maximum total temperature reaches above 1000 K, the purging time is not less than 45 s; when the maximum total temperature reaches above 700 K, the purging time is not less than 30 s; when the maximum total temperature reaches above 500 K, the purging time is not less than 15 s; when the maximum total temperature reaches above 400 K, the purging time is not less than 10 s.

[0114] During the air purging process, the main control system performs timing monitoring. When it monitors that the purging time reaches the target time, the main control system simultaneously issues a shutdown signal for the cooling system and a return signal for the variable Mach nozzle, and then the cooling system shuts down and the variable Mach nozzle returns to the preset initial position of the nozzle.

[0115] Figure 5 The figure shows a schematic flow chart of the implementation of the cooling emergency stop operation of the variable Mach wind tunnel control method provided by the embodiment of the present application.

[0116] In an embodiment of the present application, the method further includes cooling emergency stop control, which specifically includes:

[0117] Operation 401: When a cooling emergency stop signal is received, send a shutdown signal to the combustion heater and the variable Mach nozzle so that the variable Mach nozzle and the combustion heater respond to the shutdown signal and shut down;

[0118] Operation 402: When the shutdown of the variable Mach nozzle and the combustion heater is completed, detect the faulty cooling system that triggered the cooling emergency stop signal and send a shutdown signal to the faulty cooling system;

[0119] Operation 403: When the shutdown of the faulty cooling system is completed, send a shutdown signal to the low-pressure exhaust system so that the low-pressure exhaust system responds to the shutdown signal and shuts down;

[0120] Operation 404: When the shutdown of the low-pressure exhaust system is completed, send a shutdown signal to other cooling systems.

[0121] Excessive pressure of the cooling water in the cooling system can cause the equipment to be damaged by water pressure. At this time, it is necessary to stop the cooling system first under the premise that the equipment is not damaged by high temperature. When the main control system receives this cooling emergency stop signal, it sends a shutdown signal to the combustion heater and the variable Mach nozzle. After receiving the shutdown signal, regardless of the current state, the variable Mach nozzle directly stops actuating and maintains its position unchanged. After receiving the shutdown signal, the combustion heater shuts down according to the normal process (disconnecting the combustion and the supply of combustion aids), and sends a shutdown completion signal to the main control system after the shutdown is completed. 1 s after receiving the shutdown signal, the main control system sends a shutdown signal to the cooling system that detects the fault. On the other hand, when the combustion heater sends a shutdown completion signal to the main control system after completing the shutdown, the main control system sends a shutdown signal to the low-pressure exhaust system. After receiving the signal, the low-pressure exhaust system starts to shut down according to the slow shutdown process and sends a completion signal after the shutdown is completed. 60 s after receiving the shutdown completion signal of the low-pressure exhaust system, the main control system sends a shutdown signal to other cooling systems.

[0122] Figure 6 The figure shows a schematic diagram of the implementation process of the fault emergency stop operation of the variable Mach wind tunnel control method provided by the embodiment of the present application.

[0123] Reference Figure 6 In an embodiment of the present application, the method further includes a fault emergency stop operation, and the variable Mach wind tunnel further includes a fault system. The fault emergency stop operation may specifically include:

[0124] Operation 501: Receive a fault emergency stop signal sent by the fault system when a fault is detected;

[0125] Operation 502: Send a shutdown signal to the combustion heater and the variable Mach nozzle so that the variable Mach nozzle and the combustion heater respond to the shutdown signal and shut down;

[0126] Operation 503: When the shutdown of the variable Mach nozzle and the combustion heater is completed, send a shutdown signal to the low-pressure exhaust system to cause the low-pressure exhaust system to shut down in response to the shutdown signal.

[0127] Operation 504: When the shutdown of the low-pressure exhaust system is completed, send a shutdown signal to all cooling systems.

[0128] When a failure of the variable Mach wind tunnel itself causes it to malfunction, the variable Mach wind tunnel needs to be stopped immediately. However, the cooling system should continue to operate to prevent the variable Mach wind tunnel from being damaged by high temperatures. After a failure occurs, the faulty system sends a fault emergency stop signal to the main control system. When the main control system receives the fault emergency stop signal, it sends a shutdown signal to the combustion heater and the variable Mach nozzle. After receiving the shutdown signal, the variable Mach nozzle directly stops actuating and maintains its position regardless of its current state. After receiving the shutdown signal, the combustion heater shuts down according to the normal process (disconnecting the fuel supply and the combustion promoter supply). After the shutdown is completed, it sends a shutdown completion signal to the main control system. 0.5 s after receiving the shutdown signal, the main control system sends a shutdown signal to the low-pressure exhaust system. 60 s after the shutdown of the low-pressure exhaust system is completed, the main control system sends a shutdown signal to all cooling systems.

[0129] In this way, the method of the embodiment of the present application ensures the compatibility of the control logics of the various systems of the variable Mach wind tunnel and the coordinated operation of the various systems of the variable Mach wind tunnel, which is safe and reliable, through the design of the startup, shutdown, cooling emergency stop, and fault emergency stop operations of the variable Mach wind tunnel.

[0130] It should be understood that the various forms of the process shown above can be used, steps can be reordered, added, or deleted. For example, the steps described in the present application can be executed in parallel, sequentially, or in a different order, as long as the desired results of the technical solutions disclosed in the present application can be achieved. This is not limited herein.

[0131] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should be covered by the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claimed rights.

Claims

1. A variable Mach wind tunnel control method, characterized in that: A main control system applied to a variable Mach wind tunnel, wherein the variable Mach wind tunnel further comprises a combustion heater and a variable Mach nozzle, and the method comprises: When it is detected that the test environment is established, test requirement data is obtained, wherein the test requirement data includes a test environment group and a test mode, wherein the test environment group includes a plurality of target working conditions and working condition parameters of each target working condition, and the test mode includes a steady-state test mode and a dynamic test mode; In the case where the test mode is a steady-state test mode, the variable Mach wind tunnel is controlled based on the steady-state operating condition switching mechanism to simulate and test the flight environment corresponding to each target operating condition based on the multiple target operating conditions and the operating condition parameters of each target operating condition; the steady-state operating condition switching mechanism includes: judging flow field instability according to the operating condition parameters of the current operating condition and the operating condition to be switched; determining the switching path between the current operating condition and the operating condition to be switched according to the flow field instability judgment result; controlling the variable Mach nozzle and the combustion heater to perform actions corresponding to the switching path, so as to control the variable Mach wind tunnel to switch from the current operating condition to the operating condition to be switched; When the test mode is a dynamic test mode, the variable Mach wind tunnel is controlled based on a dynamic operating condition switching mechanism to simulate and test the flight environment corresponding to each target operating condition based on the multiple target operating conditions and the operating condition parameters of each target operating condition; the dynamic operating condition switching mechanism includes: discretizing the switching paths of the current operating condition and the operating condition to be switched into multiple discrete operating conditions according to a discrete segmentation method and the operating condition parameters of the current operating condition and the operating condition to be switched; controlling the variable Mach nozzle and the combustion heater to perform actions corresponding to the multiple discrete operating conditions, so as to control the variable Mach wind tunnel to switch from the current operating condition to the operating condition to be switched.

2. The method according to claim 1, characterized in that The step of determining the switching path between the current working condition and the working condition to be switched according to the flow field instability judgment result includes: If the flow field is not unstable, a switching path including the current working condition and the working condition to be switched is constructed; If the flow field is unstable, the path between the current working condition and the working condition to be switched is divided by an equal-interval dividing method until the flow field is stable, at least one transition working condition obtained by dividing is obtained, and a switching path including the current working condition, at least one transition working condition and the working condition to be switched is constructed.

3. The method according to claim 1, characterized in that: The controlling the variable Mach nozzle and the combustion heater to perform actions corresponding to the switching path includes: Obtain the working condition parameters of each working condition in the switching path; According to the operating condition parameters of each operating condition in the switching path and the execution priority mechanism, the combustion heater and the variable Mach nozzle are controlled to sequentially execute actions corresponding to each operating condition until the current operating condition is switched to the operating condition to be switched; Among them, the execution priority mechanism includes: according to the operating parameters of each operating condition, comparing the total pressure and total temperature of the incoming flow of the current operating condition and the switching operating condition to which the current operating condition needs to be switched, and comparing the switching time of the combustion heater and the switching time of the variable Mach nozzle to obtain the total pressure comparison result, the total temperature comparison result and the switching time comparison result; according to the total pressure comparison result, the total temperature comparison result, the switching time comparison result and the system synchronization mechanism, determining the startup priority and startup time of the combustion heater and the variable Mach nozzle; according to the startup priority and startup time of the combustion heater and the variable Mach nozzle and the operating parameters of the current operating condition and the switching operating condition to which the current operating condition needs to be switched, controlling the combustion heater and the variable Mach nozzle to perform corresponding actions.

4. The method according to claim 1, characterized in that: The operating parameters include Mach number; accordingly, According to the discrete segmentation method and the operating condition parameters of the current operating condition and the operating condition to be switched, the switching paths of the current operating condition and the operating condition to be switched are discretized into multiple discrete operating conditions, including: Determine the discrete number according to the Mach number of the current working condition and the working condition to be switched; According to the discrete number, the path between the current operating condition and the operating condition to be switched is discretized into a plurality of discrete operating conditions corresponding to the discrete number.

5. The method according to claim 1, characterized in that The controlling the variable Mach nozzle and the combustion heater to perform actions corresponding to a plurality of discrete operating conditions includes: Obtain the working condition parameters of each discrete working condition; According to the operating condition parameters of each discrete operating condition, the combustion heater and the variable Mach nozzle are controlled to simultaneously and sequentially execute actions corresponding to each discrete operating condition until the current operating condition is switched to the operating condition to be switched.

6. The method according to claim 1, characterized in that The variable Mach wind tunnel also includes a low-pressure exhaust system, a high-altitude test cabin, a test piece placed in the high-altitude test cabin, the variable Mach nozzle, the combustion heater, the low-pressure exhaust system and a cooling system of the high-altitude test cabin; accordingly, The test environment is established by performing the following operations: Controlling the variable Mach nozzle to move the nozzle to a preset nozzle initial position; Controlling the combustion heater to move the regulating valve to a preset valve initial position; Activate all cooling systems; Receiving an initial power-on signal, and in response to the initial power-on signal, executing a power-on operation according to a set power-on logic; When it is detected that the power-on operation is completed, it is determined that the test environment is established; Among them, the set startup logic includes: controlling the startup of the low-pressure exhaust system; when monitoring that the pressure in the high-altitude test chamber is in a stable state, controlling the combustion heater to start up, and when no startup failure signal is received from the combustion heater within a set period of time, determining that the startup operation is completed.

7. The method according to claim 6, characterized in that The method further comprises: When the test is detected to be completed, the combustion heater and the variable Mach nozzle are controlled to shut down according to the set shutdown logic; Among them, the setting of shutdown logic includes: sending a shutdown signal to the combustion heater and the variable Mach nozzle, so that the variable Mach nozzle and the combustion heater shut down in response to the shutdown signal; when the combustion heater is shut down, controlling the combustion heater to perform nitrogen purge and air purge; when the purge is completed, sending a shutdown signal to all cooling systems, and sending a nozzle return signal to the variable Mach nozzle, so that all cooling systems shut down in response to the shutdown signal, and the variable Mach nozzle moves the nozzle to a preset nozzle initial position in response to the initial return signal.

8. The method according to claim 7, characterized in that The controlling the combustion heater to perform nitrogen purge and air purge comprises: sending a nitrogen purge signal to the combustion heater, so that the combustion heater starts nitrogen purge in response to the nitrogen purge signal; When the nitrogen purge is completed, sending a shutdown signal to the low-pressure exhaust system so that the low-pressure exhaust system shuts down in response to the shutdown signal; When the low-pressure exhaust system is shut down, an air purge signal is sent to the combustion heater, so that the combustion heater performs air purge in response to the air purge signal.

9. The method according to claim 6, characterized in that The method further comprises: When receiving a cooling emergency stop signal, sending a shutdown signal to the combustion heater and the variable Mach nozzle, so that the variable Mach nozzle and the combustion heater are shut down in response to the shutdown signal; When the variable Mach nozzle and the combustion heater are shut down, detecting the faulty cooling system that triggers the cooling emergency stop signal, and sending a shutdown signal to the faulty cooling system; When the shutdown of the faulty cooling system is completed, sending a shutdown signal to the low-pressure exhaust system so that the low-pressure exhaust system shuts down in response to the shutdown signal; When the shutdown of the low-pressure exhaust system is completed, a shutdown signal is sent to other cooling systems.

10. The method according to claim 6, characterized in that The variable Mach wind tunnel also includes a fault system; accordingly, The method further comprises: Receiving a fault emergency stop signal sent by the fault system when a fault is detected; Sending a shutdown signal to the combustion heater and the variable Mach nozzle, so that the variable Mach nozzle and the combustion heater are shut down in response to the shutdown signal; When the variable Mach nozzle and the combustion heater are shut down, a shutdown signal is sent to the low-pressure exhaust system, so that the low-pressure exhaust system shuts down in response to the shutdown signal; When the shutdown of the low-pressure exhaust system is completed, a shutdown signal is sent to all cooling systems.

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