A transient supersonic wind tunnel low sonic boom test device and data acquisition method

Abstract

The invention discloses a transient supersonic wind tunnel low sonic boom test device and a data acquisition method, belonging to the technical field of wind tunnel test, comprising a wind tunnel wall plate, a model, a supporting device, an attitude and position control device and a pressure measuring rail; the model is connected as a whole with the attitude and position control device through the supporting device, the attitude and position control device and the pressure measuring rail are fixedly arranged in the wind tunnel wall plate, a plurality of equally spaced pressure measuring holes are sequentially arranged at the top end of the pressure measuring rail along the airflow direction, the front end pressure measuring holes are connected with a tee through a pipeline, the tee is respectively connected with a predetermined number of electronic pressure scanning valves through a multi-way pipe, and some of the pressure measuring holes are connected with the electronic pressure scanning valves through the pipeline; the tee is also connected with an absolute pressure sensor, and the scheme can eliminate the limitation on the measuring range of the measuring device, is applicable to any supersonic wind tunnel with the basic conditions for low sonic boom measurement test, and solves the problem that the current technical means are not universal.

Description

Technical Field

[0001] The invention relates to the technical field of wind tunnel testing, and in particular to a transient supersonic wind tunnel low sonic explosion testing device and a data acquisition method. Background Art

[0002] When the aircraft speed reaches supersonic speed, the incoming flow is compressed at the aircraft head and the leading edge of the wing to generate shock waves. The airflow is affected by the shock waves and the static pressure increases, making it higher than the initial incoming flow static pressure. Then the airflow is expanded at the fuselage and wings to generate expansion waves. The airflow is affected by the expansion waves and the static pressure decreases, making it lower than the initial incoming flow static pressure. The airflow generates shock waves at the tail of the aircraft, causing the static pressure of the aircraft flow to increase due to the shock waves, and finally returns to the far front incoming flow pressure. The shock waves and expansion waves cause the air pressure around the supersonic aircraft to fluctuate violently relative to the flight environment pressure, which is called near-field low sonic boom overpressure. The pressure wave formed by the near-field low sonic boom overpressure propagates nonlinearly in the air to the ground, forming a huge explosion sound, which is what people usually call low sonic boom. Low sonic boom is a great noise pollution that will seriously affect people's lives and work. The huge energy of low sonic boom may even damage ground buildings. Therefore, low sonic boom is a must-have feature for civil supersonic aircraft.

[0003] Wind tunnel testing is an important means of conducting low sonic boom research. Limited by the size of existing supersonic wind tunnels, the current low sonic boom wind tunnel test technology is mainly conducted in the near-field range (usually a range with a radius several times the length of the aircraft). The core of the low sonic boom wind tunnel test technology is to measure the pressure distribution in the near-field space of the aircraft model in a supersonic wind tunnel. The difference between the near-field pressure data around the model and the free flow environment pressure represents the near-field low sonic boom overpressure of the aircraft.

[0004] The low sonic boom test device in the prior art, such as a low sonic boom supersonic civil aircraft low sonic boom characteristic wind tunnel test measurement device disclosed in application number: CN202311412802.9; it has the problems of poor versatility, limited measurement range of the pressure measuring rail, high test risk or affected test data accuracy, and the pressure measurement value of the cave wall pressure measuring hole located in the wall boundary layer is greatly affected by the change of the wall state, and it is not easy to measure accurately.

[0005] The accuracy of the traditional supersonic wind tunnel low sonic boom test data acquisition method is based on the low sonic boom test device. At the same time, the accuracy of the test data is not only related to the low sonic boom test device, but also has the following problems:

[0006] Low sonic boom tests abroad are mainly carried out in continuous supersonic wind tunnels. If the reference step data is found to be abnormal, the wind tunnel itself can run continuously for a long time, which means that there is sufficient time to troubleshoot the problem. Even if the problem cannot be solved in the test, since the continuous wind tunnel runs relatively independently and does not rely on external air sources, the invalidity of a single test will only cause a certain loss in the test cost and will not have a major impact on the test efficiency.

[0007] At present, there is no continuous supersonic wind tunnel in China, and domestic low sonic boom tests are all carried out based on transient supersonic wind tunnels. Once this problem occurs in the transient wind tunnel low sonic boom test, in addition to causing the entire test train to become an invalid train, at the same time, compared with the test time of tens of seconds in conventional tests, low sonic boom tests require more measurement steps and longer collection time. The usual test time is hundreds of seconds, which is an order of magnitude higher than conventional tests. For large transient supersonic wind tunnels, the gas consumption is extremely large. If there is a problem in obtaining the reference step data in the last test step, it is almost as if the entire test train has been completed, which will cause a huge loss in test costs. In addition, the large gas consumption may result in a very limited number of test trains that can be carried out per day for low sonic boom tests, and invalid trains will greatly affect the test efficiency. Taking the low sonic boom test in a 2-meter-class transient supersonic wind tunnel as an example, the test Mach number is 1.6, the measurement steps are 30, the reference step is 1, the acquisition time for each step is 2s, and the single test time is close to 300s. The air source pressure will be reduced by about 9 atmospheres. According to the maximum air source pressure of 20 atmospheres, it can only meet the needs of 1~2 low sonic boom tests. Therefore, it is necessary to solve the reference vehicle problem to ensure that the low sonic boom test has a high cost-effectiveness. Summary of the invention

[0008] The purpose of the present invention is to provide a short-term supersonic wind tunnel low sonic boom test device and data acquisition method to address the above shortcomings, and solve the problems of poor versatility, limited measurement range of pressure rail, high test risk or affected test data accuracy in the low sonic boom test device in the prior art; at the same time, it solves the problem that the traditional supersonic wind tunnel low sonic boom test data acquisition method, if some measurement steps are invalid due to some reasons, at most the amount of low sonic boom test data will be reduced, which may have a certain impact on the test accuracy, but if there is a problem with the reference step data, the entire test train will become an invalid train. As the test time increases, the probability of problems with the wind tunnel operating parameters, model motion control and pressure acquisition system increases accordingly. Compared with the measurement step, the reference step acquisition is at the end of the entire test, and the probability of problems with its data is much higher than that of the measurement step.

[0009] The present invention is achieved through the following scheme:

[0010] A transient supersonic wind tunnel low sonic explosion test device comprises a wind tunnel wall plate, a model, a supporting device, an attitude and position control device and a pressure measuring rail; the model is connected to the attitude and position control device as a whole through the supporting device, the attitude and position control device and the pressure measuring rail are fixedly arranged in the wind tunnel wall plate, a plurality of equally spaced pressure measuring holes are sequentially arranged at the top end of the pressure measuring rail along the airflow direction, the front end pressure measuring holes are connected to a tee through a pipeline, the tee is respectively connected to a predetermined number of electronic pressure scanning valves through a multi-way pipe, some of the pressure measuring holes are connected to the electronic pressure scanning valves through pipelines, and the tee is also connected to an absolute pressure sensor.

[0011] Based on the structure of the above-mentioned transient supersonic wind tunnel low sonic explosion test device, the pressure measuring holes arranged in sequence along the airflow direction of the pressure measuring rail are defined as P1, P2...P N , N is an integer, and the P2~P N The pressure measuring hole is connected to the measuring end of the electronic pressure scanning valve through the air pipeline, the P1 pressure measuring hole is connected to the tee through the air pipeline, one end of the tee is connected to the absolute pressure sensor through the air pipeline, and the other end is connected to the reference end of the electronic pressure scanning valve through the air pipeline.

[0012] Based on the structure of the above-mentioned transient supersonic wind tunnel low sonic boom test device, the model in the supersonic airflow will generate various wave systems, which will cause pressure changes near the model and form a near-field pressure change influence zone. The P1 pressure measuring hole is outside the near-field pressure change influence zone caused by the model and maintains a predetermined distance.

[0013] The present invention also discloses a method for acquiring data from a transient supersonic wind tunnel low sonic boom test. The method is based on the above-mentioned test device and comprises the following steps:

[0014] a. Define the first reference step. According to the test requirements, the wave system generated by the model is located downstream of the last pressure measuring point of the pressure measuring rail when it propagates to the top of the pressure measuring rail, which is defined as the first reference step;

[0015] b. Start the wind tunnel and establish a supersonic flow field;

[0016] c. Collecting pressure data of the first reference step; including the pressure measured by the electronic pressure scanning valve and the pressure measured by the absolute pressure sensor;

[0017] d. Define the first measurement step and collect pressure data. The attitude and position control device controls the model to move in the axial direction to a position where the pressure change caused by the wave system generated by the model propagates to the top of the pressure measuring rail and can be completely captured by the pressure measuring rail. This is defined as the first measurement step, and the pressure data of the first measurement step is collected; including the pressure measured by the electronic pressure scanning valve and the pressure measured by the absolute pressure sensor;

[0018] e. Control the model to move n measurement steps in sequence along the axial direction at given intervals through the attitude and position control device, and collect the pressure value corresponding to each measurement step;

[0019] f. Define the second reference step and collect pressure data, control the model to move downstream in the axial direction to the first reference step position through the attitude and position control device, and the model step at this time is defined as the second reference step; and collect pressure data of the second reference step, including the pressure measured by the electronic pressure scanning valve and the pressure measured by the absolute pressure sensor;

[0020] g. Wind tunnel shutdown;

[0021] h. The characteristic parameter used to characterize the low sonic boom signal in the low sonic boom test is the overvoltage dp. When the second reference step data is successfully obtained in the test and when the second reference step data is not obtained in the test, dp ji Calculate; where j represents the jth measurement step, j=1~n, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail;

[0022] i. Define the axial position of the first pressure measuring point on the pressure measuring rail located at the upstream end as 0, and the position of each subsequent pressure measuring point relative to the first pressure measuring point as x i , i=2~m, x1=0, represents the i-th pressure measuring point on the pressure measuring rail, m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail, and the dp plotted ji ~x i The curve is the low sonic boom signal curve of the model under the jth measurement step when the model is given a posture and at a predetermined height position from the pressure measuring rail. The low sonic boom signal generated by the model is analyzed based on the above curve.

[0023] In a, specifically, before the wind tunnel is started, the height between the model and the pressure measuring rail is adjusted according to the test requirements, and the axial position of the model is adjusted so that the wave system generated by the model is located downstream of the last pressure measuring point of the pressure measuring rail when it propagates to the top of the pressure measuring rail, that is, the pressure change caused by the wave system generated by the model cannot be captured by the pressure measuring rail. At this time, the pressure value measured at each pressure measuring point on the pressure measuring rail is the pressure when it is not disturbed by the model wave system. At this time, the model step is defined as the first reference step, and the corresponding pressure data is the first reference step pressure data.

[0024] In c, specifically, the relative pressure value of each pressure measuring point of the pressure measuring rail when the pressure acquisition system acquires the model at the current position is recorded as p' reference-1i , the absolute pressure of the first measuring point measured by the absolute pressure sensor, denoted as P absolutate-1 , then the pressure data of each pressure measuring point on the pressure measuring rail at the first reference step of the model is p reference-1i , p reference-1i =p' reference-1i +Pabsolutate-1 , where 1 represents the first reference step, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail.

[0025] In d, specifically, the model is controlled by the attitude and position control device to move in the axial direction to the position where the pressure change caused by the wave system generated by the model propagates to the top of the pressure measuring rail and can be completely captured by the pressure measuring rail, which is defined as the first measurement step. The pressure acquisition system collects the pressure values ​​of each pressure measuring point of the pressure measuring rail when the model is at the current position, which is defined as the pressure data of the first measurement step of the model, recorded as p' measure-1i , where 1 represents the first measurement step, i=2~m represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail. The absolute pressure of the first measuring point measured by the absolute pressure sensor is recorded as P absolutate-2 , then p measure-1i =p' measure-1i +P absolutate-2 , p measure-1i It is the pressure data of each pressure measuring point of the pressure measuring rail during the first measurement step.

[0026] In e, specifically, the model is controlled by the attitude and position control device to move n measurement steps in the axial direction (along the airflow direction) at a given interval, and the relative pressure value corresponding to each measurement step is collected, which is recorded as p' measure-ji , where j represents the jth measurement step, j=1~n, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail; the absolute pressure of the first measuring point in the current measurement step is measured by the absolute pressure sensor and recorded as P absolutate-3 , then p measure-ji =p' measure-ji +P absolutate-3 ;p measure-ji为 The measured pressure values ​​corresponding to each measurement step.

[0027] In f, specifically, the model is controlled by the attitude and position control device to move downstream in the axial direction to the first reference step position. The model step at this time is defined as the second reference step, and the corresponding pressure data is the second reference step pressure data, recorded as p' reference-2i , where 2 represents the second reference step, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail; the absolute pressure of the first measuring point measured by the absolute pressure sensor is recorded as P absolutate-4 , p reference-2i =p' reference-2i +P absolutate-4 ;p reference-2i The pressure data of each pressure measuring point of the pressure measuring rail at the second reference step.

[0028] In h, specifically, the characteristic parameter used to characterize the low sonic boom signal in the low sonic boom test is the overvoltage dp. When the test successfully obtains the second reference step data, it is calculated according to the following formula:

[0029] dp ji =(p measure_ji -p s-measure_j ) / p s-measure_j -(p reference_2i -p s-reference ) / p s-reference , where p s-measure_j Indicates the static pressure value of the incoming flow at the jth measurement step, j=1~n, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail, p s-reference Indicates the static pressure value of the incoming flow at the second reference step;

[0030] When the test does not obtain the second reference step data, it is calculated according to the following formula:

[0031] dp ji =(p measure_ji -p s-measure_j ) / p s-measure_j -(p reference_1i -p s-reference ) / p s-reference , where p s-measure_j Indicates the static pressure value of the incoming flow at the jth measurement step, j=1~n, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail, p s-reference Indicates the static pressure value of the incoming flow at the first reference step.

[0032] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0033] In the low sonic boom test device of this scheme, the first point of the pressure measuring rail is used as the reference end of the electronic pressure scanning valve. The function realized is consistent with the cave wall pressure measuring hole, which can meet the use requirements of the low-range electronic pressure scanning valve, but is no longer restricted by the wind tunnel conditions. Whether the core test area of ​​the wind tunnel has reserved cave wall pressure measuring holes, whether the positions of the reserved cave wall pressure measuring holes and the layout positions of the pressure measuring rails match, and whether the wind tunnel allows the opening of cave wall pressure measuring holes are no longer factors that restrict the use of low-range electronic pressure scanning valves in low sonic boom measurement wind tunnel tests. The wind tunnels that can be used to carry out low sonic boom measurement tests have more selectivity and stronger versatility. At the same time, there are fewer constraints on the size and installation position of the pressure measuring rail, making its design more flexible. When designing the pressure measuring rail in the low sonic boom test device of this scheme, it is considered that the pressure measuring hole on it should be free from the influence of its own structure and the structure of the wind tunnel body to ensure the high reliability of the test results. Therefore, the pressure measurement results of the pressure measuring hole on it are more stable and reliable, and the reference end and the measuring end are both pressure measuring points on the pressure measuring rail. The wind tunnel test environment they are in is closer, which can better ensure that the pressure difference between the measuring end and the reference end of the electronic pressure scanning valve is within the range. At the same time, the length of the air pipeline is easier to unify, which is conducive to ensuring the synchronization of the reference end pressure measured by the absolute pressure sensor and the pressure of the electronic pressure scanning valve. In the low sonic boom test device of this scheme, once there is a problem with the first point pressure measuring hole, the reference end can be quickly replaced with an adjacent measuring point to ensure that the test continues, and there will be no problems with the cave wall pressure measuring hole. It is not necessary to have a replaceable cave wall pressure measuring hole, which affects the implementation of the test. The method for acquiring data for a supersonic wind tunnel low sonic boom test of this scheme first acquires reference step data and determines the validity of the data before the main part of the low sonic boom test begins. Once the data is confirmed to be invalid, the wind tunnel can be shut down in time to reduce unnecessary gas consumption and indirectly improve test efficiency. If the first reference step data is valid, the low sonic boom test can be completed according to the normal timing. If the second reference step data is successfully acquired, a high-precision test result can be obtained for the current low sonic boom test. If part of the measurement step or the second reference step data is not successfully acquired, a low sonic boom test result with a certain degree of accuracy can be obtained based on the first reference step and the part of the measurement step data that has been acquired, so that there will be no test trips that consume a lot of gas and are completely invalid. Description of the drawings

[0034] Figure 1 It is a structural schematic diagram of an existing low sonic boom test device;

[0035] Figure 2 It is a structural schematic diagram of the low sonic explosion test device of the present invention;

[0036] Figure 3 This is a schematic diagram of the low sonic explosion test model and the pressure rail installation;

[0037] Figure 4 Schematic diagram of the relative position of the model and the pressure rail for the measurement step and reference step of the low sonic boom test;

[0038] Figure 5 is a dp~x curve graph based on the first and second reference step data;

[0039] Figure 6 dp~x curves with / without reference step data;

[0040] Figure numerals: 1. wind tunnel wall panel; 2. model; 3. support device; 4. attitude and position control device; 5. pressure measuring rail; 6. pressure measuring hole; 7. air pipeline; 8. electronic pressure scanning valve; 9. pressure measuring hole on the tunnel wall; 10. tee; 11. absolute pressure sensor; 12. near-field pressure change influence area caused by the model; 13. multi-way pipe. DETAILED DESCRIPTION

[0041] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0042] Any feature disclosed in this specification (including any additional claims and abstract), unless otherwise stated, may be replaced by other alternative features that are equivalent or have similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0043] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a predetermined direction, be constructed and operated in a predetermined direction, and therefore cannot be understood as a limitation on the present invention.

[0044] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0045] Example 1

[0046] Before introducing this embodiment, the conventional low sonic boom test device is first introduced. For a test device with a low sonic boom, the corresponding near-field low sonic boom overpressure signal is weak (usually less than 1 kPa), and a low-range (usually less than 5 psid) differential pressure scanning valve is usually used for measurement. The current test device is as follows: Figure 1As shown, it includes a wind tunnel wall panel 1, a model 2, which is connected to a model posture and position control device 4 through a supporting device 3, so as to achieve adjustment of the model posture and position, and also includes a pressure measuring rail 5 of a pressure measuring device, at the top of which pressure measuring holes 6 are arranged in sequence along the airflow direction, the pressure measuring holes 6 are connected to the measuring end of an electronic pressure scanning valve 8 through an air pipeline 7, and a cave wall pressure measuring hole 9 is also provided at the front end, which is connected to a tee 10 through an air pipeline, one end of the tee 10 is connected to an absolute pressure sensor 11, so as to achieve accurate measurement of the pressure of the cave wall pressure measuring hole 9, and the other end of the tee 10 is connected to the reference end of the electronic pressure scanning valve 8 through an air pipeline. The near-field pressure change influence area 12 caused by the model in the figure is also the area that the pressure measuring rail needs to measure. When the wind tunnel flow field is established, the near-field pressure change generated by the model is propagated to the area where the pressure measuring rail 5 is located and is obtained by the electronic pressure scanning valve 8 through the pressure measuring hole 6 arranged thereon. Since the reference end of the electronic pressure scanning valve 8 is connected to the pressure measuring hole 9 on the cave wall, the pressure value at this time is the difference relative to the pressure of the pressure measuring hole 9 on the cave wall at the same time. The pressure value obtained by adding the difference and the pressure of the pressure measuring hole 9 on the cave wall measured by the absolute pressure sensor 11 is the near-field pressure change caused by the model.

[0047] The above are only the pressure measurement results of the model at one position along the airflow direction. In order to eliminate the influence of the spatial and temporal inhomogeneity of the wind tunnel flow field on the low sonic boom test results, it is usually necessary to obtain the pressure measurement results of the model at multiple positions along the airflow direction. Finally, it is also necessary to control the model away from the pressure measuring rail, that is, to ensure that the influence area of ​​the near-field pressure change caused by the model is away from the pressure measuring rail. At this time, the pressure measurement results obtained by the pressure measuring rail are used as the wind tunnel pressure results when not affected by the model, and are used for data processing to obtain the final test results.

[0048] The above technical means have achieved the effect of significantly reducing the pressure difference between the measuring end and the reference end of the electronic pressure scanning valve. The low-range electronic pressure scanning valve can be used under the operating conditions of the supersonic wind tunnel, solving the problem of over-range damage of the small-range electronic pressure scanning valve. However, the above technical means have the following difficulties in practical application:

[0049] First, the versatility is poor. The measurement device is usually installed in the area with the best flow field quality and uniformity in the wind tunnel, that is, the core test area of ​​the wind tunnel. In order to maintain the long-term stability and excellent flow field quality in this area, any changes to the internal surface of the wind tunnel, including the opening of pressure measuring holes, are almost not allowed. Therefore, the wind tunnels that can be selected for low sonic boom measurement tests are limited.

[0050] Second, the measuring range of the pressure measuring rail is limited. Pressure measuring holes may be reserved during the construction of the wind tunnel. If they are used as pressure measuring holes on the tunnel wall, considering that the pressure measuring holes on the tunnel wall cannot be affected by the measuring device, the pressure measuring holes should be located upstream of the measuring device and maintain a certain distance. The size and installation position of the measuring device along the airflow direction will be constrained, resulting in the number of pressure measuring holes that can be arranged along the airflow direction being limited, thereby limiting the measuring range of the measuring device. For example, assuming that the axial length of the core test area of ​​a wind tunnel is 2m, the maximum length of the pressure measuring rail is theoretically 2m, but if the reserved tunnel wall pressure measuring hole is just in the middle of the core test area, then the maximum length of the pressure measuring rail is only 1m.

[0051] Third, the test risk is high or the test data accuracy is affected. At present, all supersonic wind tunnels are binary wind tunnels, that is, the test area has a rectangular cross-section, a pair of wall panels are profile walls, and different test Mach numbers are obtained through their profile changes, and the other pair of wall panels are parallel wall panels. Usually, even if the core test area of ​​the wind tunnel has reserved cave wall pressure measuring holes, their positions are also on the parallel wall panels. At this time, in order to ensure that the cave wall pressure measuring holes, pressure measuring rail pressure measuring holes and the electronic pressure scanning valve connecting air pipeline lengths are as consistent as possible to reduce pressure delay, the pressure measuring rail also needs to be installed on the parallel wall. At this time, the area of ​​the pressure measuring rail that bears the impact load is extremely large, and there is a greater test risk, or the design of the pressure measuring rail needs to take into account the low sonic boom test and its "slender and thin" structure as much as possible and the test safety requirements that it has a certain thickness, which may sacrifice a certain degree of test data accuracy. Take a wind tunnel as an example. Its upper and lower wall panels are profiled walls, and the left and right side walls are parallel wall panels. The pressure rail usually has a structure similar to a long thin plate, and its size is 2.5m (length) × 25mm (width) × 350mm (height). When the pressure rail is arranged on the upper / lower wall panels, the area that bears the impact load is the horizontal projection area, which is about 2.5m×25mm=0.0625m 2 When the pressure rails are installed on the left and right side walls of the wind tunnel to match the pressure holes on the parallel walls, the area that bears the impact load is still the horizontal projection area, which is about 2.5m×350mm=0.875m 2 , the area increases by an order of magnitude, and the impact load also increases proportionally. The safety risks of the two tests are very different.

[0052] Fourth, the pressure measured by the cave wall pressure measuring holes located in the wall boundary layer is greatly affected by changes in the wall state and is difficult to measure accurately.

[0053] In summary, although the current technical means have solved the problem of over-range damage of low-range electronic pressure scanning valves in low sonic boom tests and can realize the use of low-range electronic pressure scanning valves under supersonic wind tunnel operating conditions, there are many constraints in the specific implementation. Or it cannot be implemented because there are no reserved cave wall pressure measuring holes and temporary addition of cave wall pressure measuring holes is not allowed, or the layout of the measuring device is restricted when using the reserved cave wall pressure measuring holes. That is, it is only applicable to specific wind tunnel test equipment that meets certain conditions and is not very universal.

[0054] Based on the above reasons, Figure 2 As shown, the present invention provides a technical solution:

[0055] A transient supersonic wind tunnel low sonic explosion test device, which at least includes but is not limited to a wind tunnel wall panel 1, a model 2, a support device 3, an attitude and position control device 4 and a pressure measuring rail 5; the model 2 is connected to the attitude and position control device 4 as a whole through the support device 3, the attitude and position control device 4 and the pressure measuring rail 5 are fixedly arranged in the wind tunnel wall panel 1, a plurality of equally spaced pressure measuring holes 6 are arranged in sequence at the top of the pressure measuring rail 5 along the airflow direction, the front end pressure measuring holes 6 are connected to a tee 10 through a pipeline, the tee 10 is respectively connected to a predetermined number of electronic pressure scanning valves 8 through a multi-way pipe 13, and some of the pressure measuring holes are connected to the electronic pressure scanning valve 8 through a pipeline; the tee 10 is also connected to an absolute pressure sensor 11.

[0056] Based on the above structure, this scheme uses the first point of the pressure measuring rail 5 as the reference end of the electronic pressure scanning valve 8, and the function realized is consistent with the cave wall pressure measuring hole 9, which can meet the use requirements of the low-range electronic pressure scanning valve 8, but is no longer restricted by the wind tunnel conditions. Whether the core test area of ​​the wind tunnel has reserved cave wall pressure measuring holes 9, whether the positions of the reserved cave wall pressure measuring holes 9 match the layout positions of the pressure measuring rail 5, and whether the wind tunnel allows the opening of cave wall pressure measuring holes 9 are no longer factors that restrict the use of the low-range electronic pressure scanning valve 8 in the low sonic boom measurement wind tunnel test. The wind tunnels that can be used to carry out low sonic boom measurement tests have more selectivity and stronger versatility. At the same time, the size and installation position of the pressure measuring rail 5 are less constrained, making its design more flexible. When the airflow collides with the model 2, a near-field pressure change influence area 12 caused by the model will be generated.

[0057] As an example, the pressure measuring holes arranged in sequence along the airflow direction of the pressure measuring rail are defined as P1, P2...P N , N is an integer, which is related to the design of the pressure rail and the scope of the wind tunnel core test area; N The pressure measuring hole is connected to the measuring end of the electronic pressure scanning valve through the air pipeline, and the P1 pressure measuring hole is connected to the tee through the air pipeline. One end of the tee is connected to the absolute pressure sensor 11 through the air pipeline to achieve accurate measurement of the P1 pressure, and the other end is connected to the reference end of the electronic pressure scanning valve through the air pipeline.

[0058] As an example, the model in the supersonic airflow will generate various wave systems, which will cause pressure changes near the model, forming a near-field pressure change influence zone, and the P1 pressure measuring hole is outside the near-field pressure change influence zone caused by the model and maintains a predetermined distance;

[0059] Of course, the reference end of the electronic pressure scanning valve is not limited to the first point of the pressure measuring rail, as long as it is located outside the influence area of ​​the near-field pressure change caused by the model, but if a pressure measuring hole closer to the upstream is selected, the effective measurement interval of the pressure measuring rail can be longer;

[0060] The pressure measuring hole of the pressure measuring rail connected to the reference end is preferably located upstream of the near-field pressure change influence area caused by the model. The upstream pressure measuring hole is not easily affected by the model, while the pressure measuring hole located downstream of the near-field pressure change influence area caused by the model may be affected by the model as the axial position of the model changes.

[0061] The pressure holes on the pressure rail connected to the reference end are designed for low sonic boom measurement tests, rather than randomly arranged pressure holes on the pressure rail. For example, a rectifying wedge is usually set at the front end of the pressure rail, and it is obviously inappropriate to arrange pressure holes at this position.

[0062] At the same time, through this scheme, the design of the pressure measuring rail takes into account that the pressure measuring holes thereon should be free from the influence of its own structure and the structure of the wind tunnel body to ensure the high reliability of the test results. Therefore, the pressure measurement results of the pressure measuring holes thereon are more stable and more reliable. Moreover, both the reference end and the measuring end are pressure measuring points on the pressure measuring rail, and the wind tunnel test environment in which they are located is closer, which can better ensure that the pressure difference between the measuring end and the reference end of the electronic pressure scanning valve is within the measuring range. At the same time, the length of the air pipeline is easier to unify, which is conducive to ensuring the synchronization of the reference end pressure measured by the absolute pressure sensor and the pressure of the electronic pressure scanning valve.

[0063] Once a problem occurs with the first pressure measuring hole, the reference end can be quickly replaced with an adjacent measuring point to ensure that the test continues. There will be no problem with the cave wall pressure measuring hole, and there may not be a replaceable cave wall pressure measuring hole, which will affect the implementation of the test.

[0064] Example 2

[0065] Before introducing this embodiment, the conventional method for acquiring data of a supersonic wind tunnel low sonic boom test is first introduced. Figure 3A schematic diagram of the installation position of the low sonic boom test device based on the pressure rail in the wind tunnel is given. The model 2 is installed on the wind tunnel wall panel 1 and the attitude and position control device 4 through the support device 3, so as to realize the spatial position and attitude change of the model. The pressure rail 5 is installed on the wind tunnel wall panel 1 (not limited to the lower wall panel shown in the schematic diagram), and a series of pressure measuring points are distributed along the axis at the top of the pressure rail 5. When the airflow environment in the wind tunnel is supersonic, the model generates a wave system as shown in the figure. These wave systems will propagate from the model position to a distance. When they propagate to the top of the pressure rail, the pressure changes they bring are captured by the pressure measuring holes arranged along the airflow direction. After a certain amount of data processing, the result obtained is the low sonic boom signal of the model under given attitude conditions and at a predetermined height position from the pressure rail;

[0066] The conventional low sonic boom test process based on pressure rail is as follows:

[0067] a. Before starting the wind tunnel, adjust the height between the model and the pressure rail according to the test requirements, and adjust the axial position of the model to ensure that the pressure change caused by the wave system generated by the model when it propagates to the top of the pressure rail can be completely captured by the pressure rail. The test step under this condition is defined as the measurement step. The relative position relationship between the model and the wave system generated by the measurement step and the pressure rail is as follows: Figure 4 Solid line shows;

[0068] b. Start the wind tunnel and establish a supersonic flow field;

[0069] c. The pressure acquisition system collects the pressure values ​​of each pressure measuring point on the pressure measuring rail when the model is in the current position, which is defined as the pressure data of the first measurement step of the model, denoted as p measure_1i , where 1 represents the first measurement step, i=1~m, represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail;

[0070] d. The wind tunnel position and angle control mechanism is used to control the model to move n measurement steps in the axial direction (along the airflow direction) at a given interval, and the pressure value corresponding to each measurement step is collected, which is recorded as p measure_ji , where j represents the jth measurement step, j=1~n, i=1~m, represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail;

[0071] e. The wind tunnel position and angle control mechanism is used to control the model to move downstream in the axial direction until the wave system generated by the model propagates to the top of the pressure measuring rail. The model is already downstream of the last pressure measuring point on the pressure measuring rail, that is, the pressure change caused by the wave system generated by the model cannot be captured by the pressure measuring rail. At this time, the pressure value measured at each pressure measuring point on the pressure measuring rail is the pressure when it is not disturbed by the model wave system. The model step at this time is defined as the reference step. The reference step corresponds to the relative position relationship between the model and the wave system it generates and the pressure measuring rail. Figure 4The dotted line shows that the corresponding pressure data is the reference step pressure data, denoted as p reference_i , i=1~m, represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail;

[0072] f. Wind tunnel shutdown;

[0073] g. The characteristic parameter used to characterize the low sonic boom signal in the low sonic boom test is the overvoltage dp, which is calculated according to the following formula:

[0074] dp ji =(p measure_ji -p s-measure_j ) / p s-measure_j -(p reference_i -p s-reference ) / p s-reference , where p s-measure_j Indicates the static pressure value of the incoming flow at the jth measurement step, j=1~n, i=1~m, represents the i-th pressure measuring point on the pressure measuring rail, m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail, p s-reference Indicates the static pressure value of the incoming flow when referring to the step;

[0075] h. Define the axial position of the first pressure measuring point on the pressure measuring rail located at the upstream end as 0, and the position of each subsequent pressure measuring point relative to the first point as x. i , i is defined as above, and the drawn dp ji ~x i The curve is the low sonic boom signal curve of the model under the jth measurement step when the model is at a given posture and at a predetermined height position from the pressure measuring rail. Based on the above curve, the low sonic boom signal generated by the model can be analyzed;

[0076] It can be seen from the low sonic boom test process and data processing that the reference step is crucial to the low sonic boom test. If part of the measurement step is invalid for some reason, it will at most reduce the amount of data in the low sonic boom test, which may have a certain impact on the test accuracy. However, if there is a problem with the reference step data, the entire test train will become an invalid train. As the test time increases, the probability of problems with the wind tunnel operating parameters, model motion control, and pressure acquisition systems increases. Compared with the measurement step, the reference step acquisition is at the end of the entire test, and the probability of data problems is much higher than that of the measurement step. Therefore, this problem must be considered in the low sonic boom test.

[0077] Based on the above reasons, the present invention provides a technical solution:

[0078] A method for acquiring data from a transient supersonic wind tunnel low sonic boom test; the method is applied to the low sonic boom test device of Example 1; the method comprises the following steps:

[0079] a. Define the first reference step. Before the wind tunnel is started, adjust the height between the model and the pressure rail according to the test requirements, and adjust the axial position of the model so that the wave system generated by the model is located downstream of the last pressure measuring point of the pressure rail when it propagates to the top of the pressure rail. That is, the pressure change caused by the wave system generated by the model cannot be captured by the pressure rail. At this time, the pressure value measured at each pressure measuring point on the pressure rail is the pressure when it is not disturbed by the model wave system. The model step at this time is defined as the first reference step, and the corresponding pressure data is the first reference step pressure data;

[0080] b. Start the wind tunnel and establish a supersonic flow field;

[0081] c. The pressure acquisition system acquires the relative pressure value of each pressure measuring point on the pressure measuring rail when the model is in the current position, recorded as p' reference-1i , the absolute pressure of the first measuring point measured by the absolute pressure sensor, denoted as P absolutate-1 , then the pressure data of each pressure measuring point on the pressure measuring rail at the first reference step of the model is p reference-1i , p reference-1i =p' reference-1i +P absolutate-1 , where 1 represents the first reference step, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail;

[0082] d. The model is controlled to move in the axial direction by the attitude and position control device to the position where the pressure change caused by the wave system generated by the model propagates to the top of the pressure measuring rail and can be completely captured by the pressure measuring rail. This is defined as the first measurement step. The pressure acquisition system collects the relative pressure values ​​of each pressure measuring point of the pressure measuring rail when the model is at the current position, which is defined as the pressure data of the first measurement step of the model, recorded as p' measure-1i , where 1 represents the first measurement step, i=2~m represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail. The absolute pressure of the first measuring point measured by the absolute pressure sensor is recorded as P absolutate-2 , then p measure-1i =p' measure-1i +P absolutate-2 , p measure-1i The pressure data of each pressure measuring point of the pressure measuring rail during the first measurement step;

[0083] e. The attitude and position control device controls the model to move n measurement steps in the axial direction at a given interval, and collects the relative pressure value corresponding to each measurement step, recorded as p' measure-ji , where j represents the jth measurement step, j=1~n, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail; the absolute pressure of the first measuring point in the current measurement step is measured by the absolute pressure sensor and recorded as P absolutate-3 , then p measure-ji =p'measure-ji +P absolutate-3 ;p measure-ji is the measured pressure value corresponding to each measurement step;

[0084] f. The model is controlled to move downstream in the axial direction to the first reference step position through the attitude and position control device. The model step at this time is defined as the second reference step, and the corresponding pressure data is the second reference step pressure data, recorded as p' reference-2i , where 2 represents the second reference step, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail; the absolute pressure of the first measuring point measured by the absolute pressure sensor is recorded as P absolutate-4 , then p reference-2i =p' reference-2i +P absolutate-4 ;p reference-2i The pressure data of each pressure measuring point of the pressure measuring rail at the second reference step;

[0085] g. Wind tunnel shutdown;

[0086] h. The characteristic parameter used to characterize the low sonic boom signal in the low sonic boom test is the overvoltage dp. When the test successfully obtains the second reference step data, it is calculated according to the following formula:

[0087] dp ji =(p measure_ji -p s-measure_j ) / p s-measure_j -(p reference_2i -p s-reference ) / p s-reference , where p s-measure_j Indicates the static pressure value of the incoming flow at the jth measurement step, j=1~n, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail, p s-reference Indicates the static pressure value of the incoming flow at the second reference step.

[0088] When the test does not obtain the second reference step data, it is calculated according to the following formula:

[0089] dp ji =(p measure_ji -p s-measure_j ) / p s-measure_j -(p reference_1i -p s-reference ) / p s-reference , where p s-measure_j Indicates the static pressure value of the incoming flow at the jth measurement step, j=1~n, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail, p s-reference Indicates the static pressure value of the incoming flow at the first reference step;

[0090] i. Define the axial position of the first pressure measuring point on the pressure measuring rail located at the upstream end as 0, and the position of each subsequent pressure measuring point relative to the first pressure measuring point as x i , i=1~m, represents the i-th pressure measuring point on the pressure measuring rail, m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail, and the dp plotted ji ~x i The curve is the low sonic boom signal curve of the model under the jth measurement step when the model is at a given posture and a predetermined height position from the pressure measuring rail.

[0091] Based on the above curves, the low sonic boom signal generated by the model can be analyzed;

[0092] This method solves the problem in the existing method that once the reference step data is abnormal, the entire test trip will be invalid, which will not only cause a huge loss of test costs, but more importantly, the test efficiency will be reduced due to the huge gas consumption of a single low sonic boom test. On the one hand, through data monitoring, if it is found that the data of the first reference step is questionable, the train can be shut down in time to minimize the gas consumption of invalid trips. On the other hand, even if there is a problem with the second reference step data, the data of the first reference step can still be used to obtain usable test results based on the current test data;

[0093] The reason why the test process of the first reference step + measurement step + second reference step is adopted instead of the test process of the first reference step + measurement step is that the low sonic boom test time is relatively long. As the test time increases, the changes in the temperature of the airflow in the wind tunnel gradually tend to be gentle, and the fluctuations in the spatial flow field of the wind tunnel also tend to be stable. At this time, the data obtained from the second reference step is closer to the working conditions corresponding to the previous measurement step data. Under the premise that the second reference step data can be successfully obtained, the final test results obtained based on the measurement step and the second reference step data have higher accuracy. Therefore, the advantage of this method is to avoid the occurrence of invalid trains and cause large unnecessary gas consumption to the greatest extent, thereby indirectly affecting the efficiency of the low sonic boom test, and at the same time, it also ensures that the low sonic boom test can obtain high-precision test data as much as possible. Although the test process of the first reference step + measurement step can also achieve the purpose of avoiding the occurrence of invalid trains and causing large unnecessary gas consumption to the greatest extent, it also reduces the accuracy of the low sonic boom test data to a certain extent.

[0094] Since it is necessary to ensure that the low sonic boom signals of all measurement step models can be fully captured by the pressure measuring rail, the axial movement interval between the measurement steps of the low sonic boom test is not large, usually only a few millimeters. In order to ensure sufficient control accuracy, the model movement speed is also controlled at the order of a few millimeters to tens of millimeters / s, but the reference step needs to make the model low sonic boom signal influence area completely in the pressure measuring rail measurement area. Therefore, the axial positions of the measurement step and the reference step model are usually far apart, usually at the meter level. If the axial movement from the first reference step to the first measurement step is completed at the same movement speed as the measurement step, the required time may reach nearly 100 seconds. Although the purpose of avoiding invalid train trips is solved, it may cause new unnecessary gas consumption. Therefore, the present invention optimizes the control strategy, and the movement between the first reference step and the first measurement step adopts a high-speed mode, and the movement speed is usually hundreds of millimeters / s. The axial movement between the measurement steps adopts a low-speed mode, and the movement between the last measurement step and the second reference step adopts a high-speed mode. While achieving the purpose of the present invention, the excessive test gas consumption caused by the adjustment of the test process is minimized.

[0095] The advantage of the present invention is that, in view of the problem that reference step data is necessary data for the low sonic boom test, before the main part of the low sonic boom test begins, the reference step data is first obtained and the validity of the data is judged. Once the data is confirmed to be invalid, the wind tunnel can be shut down in time to reduce unnecessary gas consumption and indirectly improve the test efficiency. If the first reference step data is valid, the low sonic boom test can be completed according to the conventional time sequence. If the second reference step data is successfully obtained, the low sonic boom test can obtain a high-precision test result. If part of the measurement step or the second reference step data is not successfully obtained, based on the first reference step and the obtained part of the measurement step data, a low sonic boom test result with a certain degree of accuracy can also be obtained, so that there will be no test vehicles that consume a lot of gas and are completely invalid.

[0096] At the same time, the method provided by the present invention has been applied in supersonic wind tunnel low sonic boom tests. After adopting the method described in this patent, there has been no invalid test train number due to abnormal reference train number data.

[0097] Figure 5 The dp~x curves obtained by taking the first reference step data and the second reference step data as reference step data are given. It can be seen that although the difference between the two is small, it means that the test curve after data processing with the first reference step data as the reference step data can basically reflect the changes in the low sonic boom signal of the model.

[0098] Figure 6The corresponding dp~x curves with and without reference step data are given. When there is no reference step data, the reference step data in the formula is set to zero. It can be seen that the dp~x curve without reference step data is significantly different from the dp~x curve with reference step data, which means that if there is no reference step data, the overvoltage result given by the test will be significantly distorted and the data will be completely unusable.

[0099] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for acquiring data from a transient supersonic wind tunnel low sonic boom test, characterized in that: The method is based on a transient supersonic wind tunnel low sonic explosion test device, which includes a wind tunnel wall plate, a model, a support device, an attitude and position control device and a pressure measuring rail; the model is connected to the attitude and position control device as a whole through the support device, the attitude and position control device and the pressure measuring rail are fixedly arranged in the wind tunnel wall plate, a plurality of equally spaced pressure measuring holes are sequentially arranged at the top of the pressure measuring rail along the airflow direction, the front end pressure measuring holes are connected to a tee through a pipeline, the tee is respectively connected to a predetermined number of electronic pressure scanning valves through a multi-way pipe, and some of the pressure measuring holes are connected to the electronic pressure scanning valves through pipelines; the tee is also connected to an absolute pressure sensor; The method comprises the following steps: a. Define the first reference step. According to the test requirements, the wave system generated by the model is located downstream of the last pressure measuring point on the pressure measuring rail when it propagates to the top of the pressure measuring rail. This step is defined as the first reference step. The pressure change caused by the wave system generated by the model cannot be captured by the pressure measuring rail. The pressure value measured at each pressure measuring point on the pressure measuring rail is the pressure when it is not disturbed by the model wave system. b. Start the wind tunnel and establish a supersonic flow field; c. Collecting pressure data of the first reference step; including the pressure measured by the electronic pressure scanning valve and the pressure measured by the absolute pressure sensor; d. Define the first measurement step and collect pressure data. Control the model to move in the axial direction through the attitude and position control device to a position where the pressure change caused by the wave system generated by the model propagating to the top of the pressure measuring rail can be completely captured by the pressure measuring rail. This is defined as the first measurement step, and pressure data for the first measurement step is collected; including the pressure measured by the electronic pressure scanning valve and the pressure measured by the absolute pressure sensor; e. Control the model to move n measurement steps in sequence along the axial direction at given intervals through the attitude and position control device, and collect the pressure value corresponding to each measurement step; f. Define the second reference step and collect pressure data, control the model to move downstream in the axial direction to the first reference step position through the attitude and position control device, and the model step at this time is defined as the second reference step; and collect pressure data of the second reference step, including the pressure measured by the electronic pressure scanning valve and the pressure measured by the absolute pressure sensor; g. Wind tunnel shutdown; h. The characteristic parameter used to characterize the low sonic boom signal in the low sonic boom test is the overvoltage dp. When the second reference step data is successfully obtained in the test and when the second reference step data is not obtained in the test, dp is calculated respectively. ji Calculate; where j represents the jth measurement step, j=1~n, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail; i. Define the axial position of the first pressure measuring point on the pressure measuring rail located at the upstream end as 0, and the position of each subsequent pressure measuring point relative to the first pressure measuring point as x i , i=2~m, x1=0, represents the i-th pressure measuring point on the pressure measuring rail, m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail, and the dp plotted ji ~x i The curve is the low sonic boom signal curve of the model under the jth measurement step when the model is given a posture and at a predetermined height position from the pressure measuring rail. The low sonic boom signal generated by the model is analyzed based on the curve.

2. The method for acquiring data from a transient supersonic wind tunnel low sonic boom test according to claim 1, characterized in that: In a, specifically, before the wind tunnel is started, the height between the model and the pressure measuring rail is adjusted according to the test requirements, and the axial position of the model is adjusted so that the wave system generated by the model is located downstream of the last pressure measuring point of the pressure measuring rail when it propagates to the top of the pressure measuring rail, that is, the pressure change caused by the wave system generated by the model cannot be captured by the pressure measuring rail. At this time, the pressure value measured at each pressure measuring point on the pressure measuring rail is the pressure when it is not disturbed by the model wave system. At this time, the model step is defined as the first reference step, and the corresponding pressure data is the first reference step pressure data.

3. The method for acquiring data from a transient supersonic wind tunnel low sonic boom test according to claim 1, characterized in that: In c, specifically, the relative pressure value of each pressure measuring point of the pressure measuring rail when the pressure acquisition system acquires the model at the current position is recorded as p' reference-1i , the absolute pressure of the first measuring point measured by the absolute pressure sensor, denoted as P absolutate-1 , then the pressure data of each pressure measuring point on the pressure measuring rail at the first reference step of the model is p reference-1i , p reference-1i =p' reference-1i +P absolutate-1 , where 1 represents the first reference step, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail.

4. The method for acquiring data from a transient supersonic wind tunnel low sonic boom test according to claim 3, characterized in that: In d, specifically, the model is controlled by the attitude and position control device to move in the axial direction to the position where the pressure change caused by the wave system generated by the model propagates to the top of the pressure measuring rail and can be completely captured by the pressure measuring rail, which is defined as the first measurement step. The pressure acquisition system collects the relative pressure values ​​of each pressure measuring point of the pressure measuring rail when the model is at the current position, which is defined as the pressure data of the first measurement step of the model, recorded as p' measure-1i , where 1 represents the first measurement step, i=2~m represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail. The absolute pressure of the first measuring point measured by the absolute pressure sensor is recorded as P absolutate-2 , then p measure-1i =p' measure-1i +P absolutate-2 , p measure-1i It is the pressure data of each pressure measuring point of the pressure measuring rail during the first measurement step.

5. The method for acquiring data from a transient supersonic wind tunnel low sonic boom test according to claim 1, characterized in that: In e, specifically, the model is controlled by the attitude and position control device to move n measurement steps in the axial direction according to a given interval, and the relative pressure value corresponding to each measurement step is collected, which is recorded as p' measure-ji , where j represents the jth measurement step, j=1~n, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail; The absolute pressure sensor measures the absolute pressure of the first measuring point in the current measurement step, which is recorded as P absolutate-3 , then p measure-ji =p' measure-ji +P absolutate-3 ;p measure-ji is the measured pressure value corresponding to each measurement step.

6. The method for acquiring data from a transient supersonic wind tunnel low sonic boom test according to claim 1, characterized in that: In f, specifically, the model is controlled by the attitude and position control device to move downstream in the axial direction to the first reference step position. The model step at this time is defined as the second reference step, and the corresponding pressure data is the second reference step pressure data, recorded as p' reference-2i , where 2 represents the second reference step, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, and m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail; the absolute pressure of the first measuring point measured by the absolute pressure sensor is recorded as P absolutate-4 , then p reference-2i =p' reference-2i +P absolutate-4 ;p reference-2i The pressure data of each pressure measuring point of the pressure measuring rail at the second reference step.

7. The method for acquiring data from a transient supersonic wind tunnel low sonic boom test according to claim 1, characterized in that: In h, specifically, the characteristic parameter used to characterize the low sonic boom signal in the low sonic boom test is the overvoltage dp. When the test successfully obtains the second reference step data, it is calculated according to the following formula: dp ji =(p measure_ji -p s-measure_j ) / p s-measure_j -(p reference_2i -p s-reference ) / p s-reference , where p s-measure_j Indicates the static pressure value of the incoming flow at the jth measurement step, j=1~n, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail, p s-reference Indicates the static pressure value of the incoming flow at the second reference step; When the test does not obtain the second reference step data, it is calculated according to the following formula: dp ji =(p measure_ji -p s-measure_j ) / p s-measure_j -(p reference_1i -p s-reference ) / p s-reference , where p s-measure_j Indicates the static pressure value of the incoming flow at the jth measurement step, j=1~n, i=2~m, represents the i-th pressure measuring point on the pressure measuring rail, m is the number of pressure measuring points distributed along the axial direction of the pressure measuring rail, p s-reference Indicates the static pressure value of the incoming flow at the first reference step.

8. The method for acquiring data from a transient supersonic wind tunnel low sonic boom test according to claim 1, characterized in that: The pressure measuring holes arranged in sequence along the airflow direction of the pressure measuring rail are defined as P1, P2...P N , N is an integer, and the P2~P N The pressure measuring hole is connected to the measuring end of the electronic pressure scanning valve through the air pipeline, the P1 pressure measuring hole is connected to the tee through the air pipeline, one end of the tee is connected to the absolute pressure sensor through the air pipeline, and the other end is connected to the reference end of the electronic pressure scanning valve through the air pipeline.

9. The method for acquiring data from a transient supersonic wind tunnel low sonic boom test according to claim 8, characterized in that: The model in the supersonic airflow will generate various wave systems, which will cause pressure changes near the model and form a near-field pressure change influence zone. The P1 pressure measuring hole is outside the near-field pressure change influence zone caused by the model and maintains a predetermined distance.

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