Wing torsion angle measuring method of wind tunnel test model

Abstract

The invention discloses a method for measuring a wing torsion angle of a wind tunnel test model, and belongs to the technical field of wind tunnel tests. The problem that in the prior art, a traditional wing torsion angle measuring method is low in wind tunnel test result precision due to limitation of measuring equipment is solved. According to the invention, the pressure measurement model is installed in the wind tunnel through the support, and the preparation work of the subsequent dynamic pressure test is completed; based on the fixed Mach number and Reynolds number in the same group of tests, through high dynamic pressure and low dynamic pressure tests, collecting the pressure of the pressure measuring point on each section under a plurality of attack angles, and calculating to obtain two groups of pressure coefficients and lift coefficients; obtaining the relation between the ratio of the incidence angle to the dynamic pressure of the pressure measurement model and the lift coefficient of the pressure measurement model, and obtaining the coefficient of a linear function; and substituting into a calculation formula of the torsion angle of the pressure measurement model to obtain a value of the torsion angle of the pressure measurement model. The method effectively reduces the wing torsion angle error, improves the precision and reliability of the wind tunnel test result, and can be used for measuring the wing torsion angle.

Description

Technical Field

[0001] The invention relates to a method for measuring a wing torsion angle, in particular to a method for measuring a wing torsion angle of a wind tunnel test model, and belongs to the technical field of wind tunnel tests. Background Art

[0002] During the wind tunnel test, the test scale model is installed in the central area of ​​the flow field of the wind tunnel test section through a supporting mechanism. The aerodynamic loads on the test model are measured by special equipment such as a balance or a scanning valve to obtain the aerodynamic characteristics of the model. The angle of attack, sideslip angle and roll angle of the model are generally obtained through angle sensors and video measurements.

[0003] The aircraft models in wind tunnel tests, especially those with large aspect ratios, will experience elastic deformation of their wings when subjected to loads, including bending and torsional deformations. The change in the local angle of attack of the wing after torsional deformation will have a significant impact on the aerodynamic characteristics of the aircraft test model. In order to obtain the accurate relationship between the aerodynamic characteristics of the model and the model angle, it is necessary to obtain the torsional angle of the test model wing in order to correct the aerodynamic data of the model.

[0004] In the prior art, a deformation measurement camera of a binocular vision system collects photos of an aircraft model in windy and windless states at different attitude angles to calculate the torsion of the model wing. However, the existing method of measuring wing deformation with a binocular vision system requires painting or pasting marking points on the surface of the test model, and also has high requirements on the position and viewing angle of the camera. After the camera position is fixed, it can only measure the wing deformation within the camera viewing angle. If the roll angle of the test model changes, it will take a lot of time to readjust and calibrate the camera position and viewing angle. In addition, it is impossible to accurately measure the situation when there are obstructions at the measurement position or the model vibrates.

[0005] In summary, a method for measuring the wing torsion angle of a wind tunnel test model is needed. Summary of the invention

[0006] A brief overview of the present invention is provided below in order to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to identify key or important parts of the present invention, nor is it intended to limit the scope of the present invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to a more detailed description discussed later.

[0007] In view of this, in order to solve the problem of low accuracy of wind tunnel test results caused by limitations of measurement equipment in traditional wing torsion angle measurement methods in the prior art, the present invention provides a wing torsion angle measurement method for a wind tunnel test model.

[0008] The technical solution is as follows: A method for measuring the wing torsion angle of a wind tunnel test model comprises the following steps: S1. Install the pressure test model in the wind tunnel through the support and complete the preparation work for the subsequent dynamic pressure test; S2. Based on the fixed Mach number and Reynolds number in the same set of tests, high dynamic pressure tests and low dynamic pressure tests are performed to collect the pressure at the pressure measuring points on each section at multiple angles of attack, and two sets of pressure coefficients and lift coefficients are calculated; S3. According to the two sets of pressure coefficients and lift coefficients, the calculation formula of the torsion angle of the pressure measurement model is obtained, and the relationship between the ratio of the angle of attack and the dynamic pressure of the pressure measurement model and the lift coefficient of the pressure measurement model is obtained to obtain the coefficient of the linear function; S4. Substitute the coefficient of the linear function into the calculation formula of the torsion angle of the pressure measurement model to obtain the value of the torsion angle of the pressure measurement model.

[0009] Furthermore, the step S3 specifically includes the following steps: S31. According to the consistent local angle of attack of the pressure model section under the same Mach number, the same Reynolds number and different dynamic pressures, the relationship between the local angle of attack of the pressure model section and the torsion angle of the pressure model section in the high dynamic pressure test and the low dynamic pressure test is obtained; S32. According to the relationship between the torsion angle of the pressure model section and the dynamic pressure and lift, a calculation formula for the torsion angle of the pressure model is obtained; S33. According to the consistency of the lift coefficient of the pressure-measured model under the same Mach number and the same Reynolds number, the relationship between the lift coefficient of the pressure-measured model during the high dynamic pressure test and the low dynamic pressure test is obtained; S34. Based on the results obtained in steps S31 to S33, a relationship between the ratio of the angle of attack and the dynamic pressure of the pressure measurement model and the lift coefficient of the pressure measurement model is obtained; S35. Perform linear regression calculation on the ratio of the angle of attack and the dynamic pressure of the pressure measurement model at multiple angles of attack of each section under the two test conditions of high dynamic pressure and low dynamic pressure and the lift coefficient of each section of the pressure measurement model, and obtain the coefficients of the linear function, i.e., the slope a and the constant term b; In S31, the relationship between the local angle of attack of the pressure model section and the torsion angle of the pressure model section is expressed as: ; ; in, is the local angle of attack of the pressure model section, is the angle of attack of the pressure measurement model during the high dynamic pressure test, is the angle of attack of the pressure measurement model during the low dynamic pressure test, is the torsion angle of the model section during the high dynamic pressure test, is the torsion angle of the model section during the low dynamic pressure test; In S32, the calculation formula of the torsion angle of the pressure measurement model is expressed as: ; in, is the slope of a linear function, is the lift coefficient of the pressure model, is the constant term of a linear function, is dynamic pressure; In S33, the relationship between the lift coefficient of the pressure measurement model during the high dynamic pressure test and the low dynamic pressure test is expressed as: ; in, is the lift coefficient of the pressure-measured model during the high dynamic pressure test, It is the lift coefficient of the pressure model during the low dynamic pressure test.

[0010] In S34, the relationship between the ratio of the pressure model angle of attack and the dynamic pressure and the pressure model lift coefficient is: ; ; in, is the angle of attack of the pressure measurement model during the high dynamic pressure test, is the angle of attack of the pressure measurement model during the low dynamic pressure test, is the dynamic pressure during the high dynamic pressure test, It is the dynamic pressure during the low dynamic pressure test.

[0011] The beneficial effects of the present invention are as follows: the present invention does not require specific, additional deformation measurement equipment, is not limited by factors such as model support method and model layout, and is insensitive to model vibration. The model torsion angle can be directly obtained by using the wing surface pressure measurement data, thereby obtaining more accurate test results, improving the accuracy and reliability of wind tunnel test results, and reducing test costs and time; the present invention can be applied to different test models with various support methods, and can realize the measurement of model torsion angle in any posture; the present invention can simultaneously obtain the model wing torsion angle during a normal wind tunnel pressure measurement test, thereby realizing accurate measurement and correction of subsequent aerodynamic characteristics of the model, and obtaining more accurate wind tunnel test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 A schematic diagram of a method for measuring the wing twist angle of a wind tunnel test model; Figure 2 Schematic diagram of the distribution of pressure measuring points on the wing of the pressure measurement model. DETAILED DESCRIPTION

[0013] In order to make the technical solutions and advantages of the embodiments of the present invention more clearly understood, the exemplary embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than an exhaustive list of all the embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0014] refer to Figure 1-Figure 2 The present embodiment is described in detail. A method for measuring the wing torsion angle of a wind tunnel test model specifically comprises the following steps: S1. Install the pressure test model in the wind tunnel through the support and complete the preparation work for the subsequent dynamic pressure test; S2. Based on the fixed Mach number and Reynolds number in the same set of tests, high dynamic pressure tests and low dynamic pressure tests are performed to collect the pressure at the pressure measuring points on each section at multiple angles of attack, and two sets of pressure coefficients and lift coefficients are calculated; Specifically: High dynamic pressure test refers to the test conducted under the condition of high dynamic pressure q at fixed Mach number and Reynolds number; low dynamic pressure test refers to the test conducted under the condition of low dynamic pressure q at fixed Mach number and Reynolds number; S3. According to the two sets of pressure coefficients and lift coefficients, the calculation formula of the torsion angle of the pressure measurement model is obtained, and the relationship between the ratio of the angle of attack and the dynamic pressure of the pressure measurement model and the lift coefficient of the pressure measurement model is obtained to obtain the coefficient of the linear function; S4. Substitute the coefficient of the linear function into the calculation formula of the torsion angle of the pressure measurement model to obtain the value of the torsion angle of the pressure measurement model.

[0015] Furthermore, the step S3 specifically includes the following steps: S31. According to the consistent local angle of attack of the pressure model section under the same Mach number, the same Reynolds number and different dynamic pressures, the relationship between the local angle of attack of the pressure model section and the torsion angle of the pressure model section in the high dynamic pressure test and the low dynamic pressure test is obtained; S32. According to the relationship between the torsion angle of the pressure model section and the dynamic pressure and lift, a calculation formula for the torsion angle of the pressure model is obtained; S33. According to the consistency of the lift coefficient of the pressure-measured model under the same Mach number and the same Reynolds number, the relationship between the lift coefficient of the pressure-measured model during the high dynamic pressure test and the low dynamic pressure test is obtained; S34. Based on the results obtained in steps S31 to S33, a relationship between the ratio of the angle of attack and the dynamic pressure of the pressure measurement model and the lift coefficient of the pressure measurement model is obtained; S35. Perform linear regression calculation on the ratio of the angle of attack and the dynamic pressure of the pressure measurement model at multiple angles of attack of each section under the two test conditions of high dynamic pressure and low dynamic pressure and the lift coefficient of each section of the pressure measurement model, and obtain the coefficients of the linear function, i.e., the slope a and the constant term b; In S31, the relationship between the local angle of attack of the pressure model section and the torsion angle of the pressure model section is expressed as: ; ; in, is the local angle of attack of the pressure model section, is the angle of attack of the pressure measurement model during the high dynamic pressure test, is the angle of attack of the pressure measurement model during the low dynamic pressure test, is the torsion angle of the model section during the high dynamic pressure test, is the torsion angle of the model section during the low dynamic pressure test; In S32, the calculation formula of the torsion angle of the pressure measurement model is expressed as: ; in, is the slope of a linear function, is the lift coefficient of the pressure model, is the constant term of a linear function, is dynamic pressure; In S33, the relationship between the lift coefficient of the pressure measurement model during the high dynamic pressure test and the low dynamic pressure test is expressed as: ; in, is the lift coefficient of the pressure-measured model during the high dynamic pressure test, It is the lift coefficient of the pressure model during the low dynamic pressure test.

[0016] In S34, the relationship between the ratio of the pressure model angle of attack and the dynamic pressure and the pressure model lift coefficient is: ; ; in, is the angle of attack of the pressure measurement model during the high dynamic pressure test, is the angle of attack of the pressure measurement model during the low dynamic pressure test, is the dynamic pressure during the high dynamic pressure test, It is the dynamic pressure during the low dynamic pressure test.

[0017] Although the present invention has been described according to a limited number of embodiments, it will be apparent to those skilled in the art, with the benefit of the above description, that other embodiments may be envisioned within the scope of the invention thus described. In addition, it should be noted that the language used in this specification is selected primarily for readability and teaching purposes, rather than for explaining or defining the subject matter of the present invention. Therefore, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the present invention is illustrative, not restrictive, with respect to the scope of the present invention, which is defined by the appended claims.

Claims

1. A method for measuring the wing torsion angle of a wind tunnel test model, characterized in that: The following steps are involved: S1. Install the pressure test model in the wind tunnel through supports and complete the preparation for the subsequent dynamic pressure test; S2. Based on the fixed Mach number and Reynolds number in the same set of tests, high dynamic pressure tests and low dynamic pressure tests are performed to collect the pressure at the pressure measuring points on each section at multiple angles of attack, and two sets of pressure coefficients and lift coefficients are calculated; S3. According to the two sets of pressure coefficients and lift coefficients, the calculation formula of the torsion angle of the pressure measurement model is obtained, and the relationship between the ratio of the angle of attack and the dynamic pressure of the pressure measurement model and the lift coefficient of the model is obtained to obtain the coefficient of the linear function; S4. Substitute the coefficient of the linear function into the calculation formula of the torsion angle of the pressure measurement model to obtain the value of the torsion angle of the pressure measurement model.

2. The method for measuring the wing torsion angle of a wind tunnel test model according to claim 1, characterized in that: The S3 specifically includes the following steps: S31. According to the consistent local angle of attack of the pressure model section under the same Mach number, the same Reynolds number and different dynamic pressures, the relationship between the local angle of attack of the pressure model section and the torsion angle of the pressure model section in the high dynamic pressure test and the low dynamic pressure test is obtained; S32. According to the relationship between the torsion angle of the pressure model section and the dynamic pressure and lift, a calculation formula for the torsion angle of the pressure model is obtained; S33. According to the consistency of the lift coefficient of the pressure-measured model under the same Mach number and the same Reynolds number, the relationship between the lift coefficient of the pressure-measured model during the high dynamic pressure test and the low dynamic pressure test is obtained; S34. Based on the results obtained in steps S31 to S33, a relationship between the ratio of the angle of attack and the dynamic pressure of the pressure measurement model and the lift coefficient of the pressure measurement model is obtained; S35. Perform linear regression calculation on the ratio of the angle of attack and the dynamic pressure of the pressure measurement model at multiple angles of attack of each section under the two test conditions of high dynamic pressure and low dynamic pressure and the lift coefficient of each section of the pressure measurement model, and obtain the coefficients of the linear function, i.e., the slope a and the constant term b; In S31, the relationship between the local angle of attack of the pressure model section and the torsion angle of the pressure model section is expressed as: ； ； in, is the local angle of attack of the pressure model section, is the angle of attack of the pressure measurement model during the high dynamic pressure test, is the angle of attack of the pressure measurement model during the low dynamic pressure test, is the torsion angle of the model section during the high dynamic pressure test, is the torsion angle of the model section during the low dynamic pressure test; In S32, the calculation formula of the torsion angle of the pressure measurement model is expressed as: ； in, is the slope of a linear function, is the lift coefficient of the pressure model, is the constant term of a linear function, is dynamic pressure; In S33, the relationship between the lift coefficient of the pressure measurement model during the high dynamic pressure test and the low dynamic pressure test is expressed as: ； in, is the lift coefficient of the pressure-measured model during the high dynamic pressure test, is the lift coefficient of the pressure-measured model during the low dynamic pressure test; In S34, the relationship between the ratio of the pressure model angle of attack and the dynamic pressure and the pressure model lift coefficient is: ； ； in, is the angle of attack of the pressure measurement model during the high dynamic pressure test, is the angle of attack of the pressure measurement model during the low dynamic pressure test, is the dynamic pressure during the high dynamic pressure test, It is the dynamic pressure during the low dynamic pressure test.

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