Method for correcting tail support interference of wind tunnel test model

Abstract

The invention discloses a method for correcting tail support interference of a wind tunnel test model, and belongs to the technical field of aircraft wind tunnel tests. In order to achieve fine correction of tail support interference of different wind tunnel test models, the method comprises the steps that a row of pressure measuring points are designed and machined on the backs of symmetry planes of the wind tunnel test models; carrying out a tail support test, and calculating to obtain a pressure coefficient of a pressure measuring point of the tail support test; carrying out an under-wing double-support false tail support test, collecting pressure data of a pressure measuring point on the back of a symmetry plane of the wind tunnel test model, and calculating a pressure coefficient of the pressure measuring point of the under-wing double-support false tail support test; then, the average pressure coefficient value of the pressure measuring points on the surface of the wind tunnel test model of the under-wing double-support and false tail support test is made to be consistent with the average pressure coefficient value of the pressure measuring points on the surface of the wind tunnel test model of the tail support test, and the Mach number control relation is corrected; calculating to obtain Mach number gradient correction values of different tests and tail support tests; and calculating the interference variable of the tail support. The test result is more accurate.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft wind tunnel tests, and in particular relates to a method for correcting tail support interference of a wind tunnel test model. Background Art

[0002] In a wind tunnel test, the wind tunnel test model is installed in the center area of ​​the flow field of the wind tunnel test section through a support mechanism. For high-speed wind tunnel force measurement tests, a tail support is generally used to install the wind tunnel test model on the wind tunnel scimitar motion mechanism through a force balance and a support. In order to achieve force measurement of the wind tunnel test model and its connection with the support, it is generally necessary to install a force balance in the fuselage of the wind tunnel test model. At the same time, the support connected to the force balance needs to pass through the fuselage and be connected to the wind tunnel scimitar mechanism, which will inevitably damage the fuselage. At the same time, the support will also affect the flow field near the wind tunnel test model, thereby affecting the accuracy of the wind tunnel test model force measurement results. In order to obtain accurate aerodynamic and torque data of the wind tunnel test model, it is necessary to correct the influence of the support on the wind tunnel test model force measurement results.

[0003] For large aspect ratio aircraft, the wingspan is large, and the wind tunnel test model is generally installed in the wind tunnel test section through an underwing double support system. Specifically, the wind tunnel test model is installed in the wind tunnel through a force balance, underwing support struts, etc. on the wings on both sides of the wind tunnel test model, and the interference amount of the tail support is obtained through underwing double support system tests with and without fake tail branches.

[0004] In the prior art, a correction relationship is obtained by designing a double-support flow field calibration device under the wing and performing a special calibration test in a wind tunnel. This method does not install a wind tunnel test model in the wind tunnel during flow field calibration. The calibration relationship obtained by this method is mainly a correction for the influence of the double-support system under the wing on the flow field. The wind tunnel test model is also one of the key factors affecting the flow field in the wind tunnel test section. This method cannot calibrate the flow field of the wind tunnel test model installed in the wind tunnel, and cannot provide accurate correction relationships for different wind tunnel test models. Summary of the invention

[0005] The problem to be solved by the present invention is to perform refined correction of tail support interference of different wind tunnel test models, and a method for correcting tail support interference of wind tunnel test models is proposed.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions: A method for correcting tail support interference of a wind tunnel test model comprises the following steps: S1. Design and process a row of pressure measuring points on the back of the symmetrical surface of the wind tunnel test model; S2. Perform a tail support test and collect pressure data of the pressure measuring points on the back of the symmetric surface of the wind tunnel test model to calculate the pressure coefficient of the pressure measuring point of the tail support test; S3. Conduct a double underwing support plus fake tail branch test, collect pressure data of pressure measuring points on the back of the symmetric surface of the wind tunnel test model, calculate the pressure coefficient of the pressure measuring points of the double underwing support plus fake tail branch test, and then make the average pressure coefficient of the pressure measuring points on the surface of the wind tunnel test model of the double underwing support plus fake tail branch test consistent with the average pressure coefficient of the pressure measuring points on the surface of the wind tunnel test model of the tail support test, and correct the Mach number control relationship; S4. Based on the Mach number control relationship corrected in step S3, a double underwing support plus fake tail branch test and a tail support test are performed, and the Mach number correction difference of each pressure measuring point is calculated using the measured pressure data, and then the Mach number gradient correction value of the double underwing support plus fake tail branch test and the tail support test is calculated; S5. Based on the method of step S3 and step S4, a double underwing support test is performed, and then the Mach number gradient correction value of the double underwing support test and the tail support test is calculated; S6. According to the Mach number gradient correction values ​​of steps S4 and S5, the full-aircraft force measurement test results of the tail support test, the underwing double support plus fake tail branch test, and the underwing double support test are obtained, and the interference amount of the tail support is calculated.

[0007] Furthermore, the number of pressure measuring points in step S1 is 10.

[0008] Furthermore, the specific implementation method of step S2 includes the following steps: S21. Perform the tail support test and collect the pressure of 10 pressure measuring points on the symmetrical back of the wind tunnel test model at the same time during the test. The tail support test i The pressure at each pressure measuring point; S22. Calculate the pressure coefficient of the pressure measuring point on the back of the symmetric surface of the wind tunnel test model for the tail support test. The calculation method is as follows: Calculating the Mach number of the wind tunnel flow field for the tail support test , the calculation formula is: ; ; in, is the reference pressure Mach number of the wind tunnel chamber, for and The correction amount, is the total pressure in the wind tunnel stable section, is the static pressure in the wind tunnel chamber, The value is determined by flow field calibration in each test section of each wind tunnel; Setting the static pressure of the wind tunnel test section The calculation formula is: ; The rear support test wind tunnel model has the following symmetry plane: Pressure coefficient of each pressure measuring point The calculation formula is: .

[0009] Furthermore, the specific implementation method of step S3 includes the following steps: S31. Conduct a double underwing support plus fake tail branch test, and collect pressure at the back of the symmetrical surface of the wind tunnel test model during the test. This is the first test of the double underwing support plus fake tail branch. i The pressure of the pressure measuring point is then calculated to obtain the pressure of the symmetrical surface of the wind tunnel test model of the double support underwing plus fake tail branch test. Pressure coefficient of each pressure measuring point , the calculation formula is: ; S32. Compare the pressure coefficients during the tail support test and calculate the difference between the average pressure coefficients of the 10 pressure measuring points during the two tests. , the calculation formula is: ; S33. Adjust the static pressure value of the wind tunnel test section flow field of the double support with fake tail branch test under the wing , to achieve the same average pressure coefficient of the back pressure measuring point at the symmetric surface position during the tail support and underwing double support with fake tail branch tests. The calculation formula is: ; in, is the average value of the pressure coefficient of 10 pressure measuring points during the tail support test, This is the first test of the double underwing support plus fake tail branch. i The average pressure of the pressure measuring points, is the Mach number of the wind tunnel flow field of the underwing double support with fake tail branch test; at the same time, ; Calculated by the above two formulas , and then calculate the Mach number control relationship: ; in, for and The correction amount; S34. Obtained according to step S33 , a double underwing support plus fake tail branch test was carried out, and the aerodynamic force and moment data of the whole aircraft of the wind tunnel test model of the double underwing support plus fake tail branch under support conditions were obtained.

[0010] Furthermore, the specific implementation method of step S4 includes the following steps: S41. Assuming that the flow fields of different support forms are completely consistent, the pressure coefficients of each pressure measuring point should be equal, and the formula is: ; in, This is the first test of the double underwing support plus fake tail branch. i The pressure value of each pressure measuring point, The first test of double underwing support plus fake tail support i The theoretical flow field static pressure at each pressure measuring point, For the i The theoretical flow field Mach number at the pressure measuring point is: For the tail support test i The pressure coefficient of each pressure measuring point; at the same time, ; Calculate the first i Theoretical flow field Mach number at the pressure measuring point ; S42. Calculation of Mach number gradient correction value of the flow field Mach number in the test section model area during the underwing double support plus fake tail branch test and tail support test , the calculation formula is: ; in, is the Mach number of the flow field in the test section model area of ​​the underwing double support with fake tail branch test, is the distance from the entrance of the test section.

[0011] Beneficial effects of the present invention: The method for correcting the tail support interference of a wind tunnel test model described in the present invention solves the problems in the prior art of insufficient flow field correction accuracy, inability to meet the needs of refined tests, and inability to perform refined corrections for different test models, improves the accuracy and reliability of wind tunnel support interference test results, reduces test costs and time, and expands the application scope of wind tunnel tests.

[0012] The method for correcting the tail support interference of a wind tunnel test model described in the present invention can quickly obtain the correction value of the wind tunnel test flow field for different test models without the need for special flow field calibration tests.

[0013] The method for correcting the tail support interference of a wind tunnel test model described in the present invention can not only correct the Mach number accuracy of different test types, but also calculate and correct the Mach number gradient of the model area, thereby obtaining more accurate wind tunnel test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention is a flow chart of a method for correcting tail support interference of a wind tunnel test model. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention more clear, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention, that is, the specific embodiments described are only part of the embodiments of the present invention, rather than all of the specific embodiments. The components of the specific embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations, and the present invention can also have other embodiments.

[0016] Therefore, the following detailed description of the specific embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected specific embodiments of the present invention. Based on the specific embodiments of the present invention, all other specific embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present invention.

[0017] In order to further understand the content, features and effects of the present invention, the following specific implementation methods are given as examples, and the attached Figure 1 The detailed instructions are as follows:

[0018] Embodiment 1: A method for correcting tail support interference of a wind tunnel test model comprises the following steps: S1. Design and process a row of pressure measuring points on the back of the symmetrical surface of the wind tunnel test model; Furthermore, the number of pressure measuring points in step S1 is 10.

[0019] S2. Perform a tail support test and collect pressure data of the pressure measuring points on the back of the symmetric surface of the wind tunnel test model to calculate the pressure coefficient of the pressure measuring point of the tail support test; Furthermore, the specific implementation method of step S2 includes the following steps: S21. Perform the tail support test and collect the pressure of 10 pressure measuring points on the symmetrical back of the wind tunnel test model at the same time during the test. The tail support test iThe pressure at each pressure measuring point; S22. Calculate the pressure coefficient of the pressure measuring point on the back of the symmetric surface of the wind tunnel test model for the tail support test. The calculation method is as follows: Calculating the Mach number of the wind tunnel flow field for the tail support test , the calculation formula is: ; ; in, is the reference pressure Mach number of the wind tunnel chamber, for and The correction amount, is the total pressure in the wind tunnel stable section, is the static pressure in the wind tunnel chamber, The value is determined by flow field calibration in each test section of each wind tunnel; Setting the static pressure of the wind tunnel test section The calculation formula is: ; The rear support test wind tunnel model has the following symmetry plane: Pressure coefficient of each pressure measuring point The calculation formula is: .

[0020] S3. Conduct a double underwing support plus fake tail branch test, collect pressure data of pressure measuring points on the back of the symmetric surface of the wind tunnel test model, calculate the pressure coefficient of the pressure measuring points of the double underwing support plus fake tail branch test, and then make the average pressure coefficient of the pressure measuring points on the surface of the wind tunnel test model of the double underwing support plus fake tail branch test consistent with the average pressure coefficient of the pressure measuring points on the surface of the wind tunnel test model of the tail support test, and correct the Mach number control relationship; Furthermore, the specific implementation method of step S3 includes the following steps: S31. Conduct a double underwing support plus fake tail branch test, and collect pressure at the back of the symmetrical surface of the wind tunnel test model during the test. This is the first test of the double underwing support plus fake tail branch. i The pressure of the pressure measuring point is then calculated to obtain the pressure of the symmetrical surface of the wind tunnel test model of the double support underwing plus fake tail branch test. Pressure coefficient of each pressure measuring point , the calculation formula is: ; S32. Compare the pressure coefficients during the tail support test and calculate the difference between the average pressure coefficients of the 10 pressure measuring points during the two tests. , the calculation formula is: ; S33. Adjust the static pressure value of the wind tunnel test section flow field of the double support with fake tail branch test under the wing , to achieve the same average pressure coefficient of the back pressure measuring point at the symmetric surface position during the tail support and underwing double support with fake tail branch tests. The calculation formula is: ; in, is the average value of the pressure coefficient of 10 pressure measuring points during the tail support test, This is the first test of the double underwing support plus fake tail branch. i The average pressure of the pressure measuring points, is the Mach number of the wind tunnel flow field of the underwing double support with fake tail branch test; at the same time, ; Calculated by the above two formulas , and then calculate the Mach number control relationship: ; in, for and The correction amount; S34. Obtained according to step S33 , a double underwing support plus fake tail branch test was carried out, and the aerodynamic force and moment data of the whole aircraft of the wind tunnel test model of the double underwing support plus fake tail branch under support conditions were obtained.

[0021] S4. Based on the Mach number control relationship corrected in step S3, a double underwing support plus fake tail branch test and a tail support test are performed, and the Mach number correction difference of each pressure measuring point is calculated using the measured pressure data, and then the Mach number gradient correction value of the double underwing support plus fake tail branch test and the tail support test is calculated; Furthermore, the specific implementation method of step S4 includes the following steps: S41. Assuming that the flow fields of different support forms are completely consistent, the pressure coefficients of each pressure measuring point should be equal, and the formula is: ; in, This is the first test of the double underwing support plus fake tail branch. i The pressure value of each pressure measuring point, The first test of double underwing support plus fake tail support i The theoretical flow field static pressure at each pressure measuring point, For the i The theoretical flow field Mach number at the pressure measuring point is: For the tail support test i The pressure coefficient of each pressure measuring point; at the same time, ; Calculate the first i Theoretical flow field Mach number at the pressure measuring point ; S42. Calculation of Mach number gradient correction value of the flow field Mach number in the test section model area during the underwing double support plus fake tail branch test and tail support test , the calculation formula is: ; in, is the Mach number of the flow field in the test section model area of ​​the underwing double support with fake tail branch test, is the distance from the entrance of the test section.

[0022] S5. Based on the method of step S3 and step S4, a double underwing support test is performed, and then the Mach number gradient correction value of the double underwing support test and the tail support test is calculated; Furthermore, the specific implementation method of step S5 includes the following steps: S51. Repeat step S3 to obtain the new flow field control relationship of the test section model area during the underwing double support test and the tail support test , and completed the underwing double support test based on the new control relationship; S52. Repeat step S4 to obtain the Mach number gradient correction value of the flow field Mach number in the test section model area during the underwing double support test and the tail support test.

[0023] S6. According to the Mach number gradient correction values ​​of steps S4 and S5, the full-aircraft force measurement test results of the tail support test, the underwing double support plus fake tail branch test, and the underwing double support test are obtained, and the interference amount of the tail support is calculated.

[0024] This implementation method designs and processes a row of pressure measuring points on the back of the symmetric surface of the wind tunnel test model, starting from the highest point of the normal position of the back of the test model nose to the position 100 mm in front of the test model tail wing. The pressure data at this position is generally less affected by the nose and tail wing. The number of pressure measuring points is generally about 10. During the test, the pressure of each pressure measuring point of the section is measured in real time and the pressure coefficient is calculated. The test items mainly include tail support test, underwing double support test, underwing double support with fake tail branch test. Taking the pressure coefficient of the pressure measuring point of the tail support test as the benchmark, the wind tunnel flow field Mach number control relationship is adjusted to make the average value of the pressure coefficient of the pressure measuring point on the model surface during the underwing double support test and the underwing double support with fake tail branch test consistent with that during the tail support test, and at the same time, the flow field Mach number gradient of the model area of ​​the test section under different support forms is obtained.

[0025] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0026] Although the present application has been described above with reference to specific embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural conflict, the various features in the specific embodiments disclosed in the present application may be used in combination with each other in any manner, and the fact that these combinations are not exhaustively described in this specification is only for the sake of omitting space and saving resources. Therefore, the present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for correcting the tail support interference of a wind tunnel test model, characterized in that: The steps include: S1. Design and process a row of pressure measuring points on the back of the symmetrical surface of the wind tunnel test model; S2. Perform a tail support test and collect pressure data of the pressure measuring points on the back of the symmetric surface of the wind tunnel test model to calculate the pressure coefficient of the pressure measuring point of the tail support test; S3. Conduct a double underwing support plus fake tail branch test, collect pressure data of pressure measuring points on the back of the symmetric surface of the wind tunnel test model, calculate the pressure coefficient of the pressure measuring points of the double underwing support plus fake tail branch test, and then make the average pressure coefficient of the pressure measuring points on the surface of the wind tunnel test model of the double underwing support plus fake tail branch test consistent with the average pressure coefficient of the pressure measuring points on the surface of the wind tunnel test model of the tail support test, and correct the Mach number control relationship; S4. Based on the Mach number control relationship corrected in step S3, a double underwing support plus fake tail branch test and a tail support test are performed, and the Mach number correction difference of each pressure measuring point is calculated using the measured pressure data, and then the Mach number gradient correction value of the double underwing support plus fake tail branch test and the tail support test is calculated; S5. Based on the method of step S3 and step S4, a double underwing support test is performed, and then the Mach number gradient correction value of the double underwing support test and the tail support test is calculated; S6. According to the Mach number gradient correction values ​​of steps S4 and S5, the full-aircraft force measurement test results of the tail support test, the underwing double support plus fake tail branch test, and the underwing double support test are obtained, and the interference amount of the tail support is calculated.

2. A method for correcting tail support interference of a wind tunnel test model according to claim 1, characterized in that: The number of pressure measuring points in step S1 is 10.

3. A method for correcting tail support interference of a wind tunnel test model according to claim 1 or 2, characterized in that: The specific implementation method of step S2 includes the following steps: S21. Perform the tail support test and collect the pressure of 10 pressure measuring points on the symmetrical back of the wind tunnel test model at the same time during the test. The tail support test i The pressure at each pressure measuring point; S22. Calculate the pressure coefficient of the pressure measuring point on the back of the symmetric surface of the wind tunnel test model for the tail support test. The calculation method is as follows: Calculating the Mach number of the wind tunnel flow field for the tail support test , the calculation formula is: ； ； in, is the reference pressure Mach number of the wind tunnel chamber, for and The correction amount, is the total pressure in the wind tunnel stable section, is the static pressure in the wind tunnel chamber, The value is determined by flow field calibration in each test section of each wind tunnel; Setting the static pressure of the wind tunnel test section The calculation formula is: ； The rear support test wind tunnel model has the following symmetry plane: Pressure coefficient of each pressure measuring point The calculation formula is: 。 4. A method for correcting tail support interference of a wind tunnel test model according to claim 3, characterized in that: The specific implementation method of step S3 includes the following steps: S31. Conduct a double underwing support plus fake tail branch test, and collect pressure at the back of the symmetrical surface of the wind tunnel test model during the test. This is the first test of the double underwing support plus fake tail branch. i The pressure of the pressure measuring point is then calculated to obtain the pressure of the symmetrical surface of the wind tunnel test model of the double support underwing plus fake tail branch test. Pressure coefficient of each pressure measuring point , the calculation formula is: ； S32. Compare the pressure coefficients during the tail support test and calculate the difference between the average pressure coefficients of the 10 pressure measuring points during the two tests. , the calculation formula is: ； S33. Adjust the static pressure value of the wind tunnel test section flow field of the double support with fake tail branch test under the wing , to achieve the same average pressure coefficient of the back pressure measuring point at the symmetric surface position during the tail support and underwing double support with fake tail branch tests. The calculation formula is: ； in, is the average value of the pressure coefficient of 10 pressure measuring points during the tail support test, This is the first test of the double underwing support plus fake tail branch. i The average pressure of the pressure measuring points, is the Mach number of the wind tunnel flow field of the underwing double support with fake tail branch test; at the same time, ; Calculated by the above two formulas , and then calculate the Mach number control relationship: ； in, for and The correction amount; S34. Obtained according to step S33 , a double underwing support plus fake tail branch test was carried out, and the aerodynamic force and moment data of the whole aircraft of the wind tunnel test model of the double underwing support plus fake tail branch under support conditions were obtained.

5. A method for correcting tail support interference of a wind tunnel test model according to claim 4, characterized in that: The specific implementation method of step S4 includes the following steps: S41. Assuming that the flow fields of different support forms are completely consistent, the pressure coefficients of each pressure measuring point should be equal, and the formula is: ； in, This is the first test of the double underwing support plus fake tail branch. i The pressure value of each pressure measuring point, The first test of double underwing support plus fake tail support i The theoretical flow field static pressure at each pressure measuring point, For the i The theoretical flow field Mach number at the pressure measuring point is: For the tail support test i The pressure coefficient of each pressure measuring point; at the same time, ; Calculate the first i Theoretical flow field Mach number at the pressure measuring point ; S42. Calculation of Mach number gradient correction value of the flow field Mach number in the test section model area during the underwing double support plus fake tail branch test and tail support test , the calculation formula is: ； in, is the Mach number of the flow field in the test section model area of ​​the underwing double support with fake tail branch test, is the distance from the entrance of the test section.

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