A continuous wind tunnel force measurement test method

Abstract

A continuous wind tunnel force measurement test method belongs to the technical field of wind tunnel force measurement tests. To solve the problem of low accuracy in continuous wind tunnel force measurement tests at relatively high Mach numbers, the present invention includes installing a wind tunnel test support system, a force measurement test balance, and a test model in the wind tunnel, conducting a no-wind test to obtain no-wind test data; conducting a windy test and collecting wind tunnel test data for different train runs; processing to obtain the loads on the test model under the action of the airflow in the wind tunnel test section; through coordinate system transformation, converting the force vector and moment vector in the balance coordinate system into the force vector and moment vector in the test model body axis system and the force vector and moment vector in the wind tunnel airflow axis system; obtaining the force coefficient vector and moment coefficient vector in the test model body axis system and the force coefficient vector and moment coefficient vector in the wind tunnel airflow axis system; respectively using the method of locally weighted linear regression to fit the curves of the aerodynamic force of the test model varying with the angle of attack and the curve of the moment coefficient varying with the angle of attack.

Description

Technical Field

[0001] The present invention belongs to the technical field of wind tunnel force measurement tests, and particularly relates to a method for continuous wind tunnel force measurement tests. Background Art

[0002] Wind tunnel force measurement tests are aerodynamic tests conducted in a wind tunnel. Mainly by installing a test model in the test section of the wind tunnel and installing a force measurement balance in the test model to measure the aerodynamic force acting on the aircraft test model or its components by the airflow. Such tests are crucial for the development of aircraft and mainly include full aircraft (missile) force measurement tests, half model force measurement tests, component force measurement tests, external store force measurement tests, hinge moment tests, etc. During the development process of an aircraft, wind tunnel force measurement tests are the test type with the highest proportion and the largest test volume, accounting for about 60% - 70% of all wind tunnel tests during the model development process.

[0003] Continuous force measurement test refers to the condition where the wind tunnel flow field is stable (Mach number, total pressure, total temperature, etc.), the attitude angle of the test model continuously changes at a fixed speed (generally less than 0.5° per second), and the data acquisition system continuously collects flow field information and the strain output by the force measurement balance to obtain the aerodynamic force data of the test model during the entire change process of the attitude angle. In contrast, the stepped force measurement test refers to the condition where the wind tunnel flow field is stable, the attitude angle of the test model changes in a given sequence of steps, and the data acquisition system collects the flow field information and the strain output by the force measurement balance of the test model at the given attitude angle sequence.

[0004] Compared with the stepped force measurement test that can only obtain the aerodynamic force data at a given attitude angle, the continuous force measurement test can obtain the aerodynamic force data of the test model from the starting angle of attack / sideslip angle to the ending angle of attack / sideslip angle. The data obtained from the continuous force measurement test has a large data density and comprehensive details, and can obtain more accurate aerodynamic characteristics (such as the maximum lift-to-drag ratio, critical angle of attack, etc.). At the same time, it is also more conducive to obtaining or discovering abnormal data during the change process of the model attitude angle. As shown in the appendix Figure 1 as follows.

[0005] However, different from the stepped test where the flow field (Mach number, total pressure, etc.) is judged stable at each attitude angle and then the flow field data and the balance strain data are collected, during the continuous force measurement test, after the flow field at the starting attitude angle is judged stable, the test model starts to continuously move at a fixed speed to the ending attitude angle, and the wind tunnel flow field may exceed the given error band during the movement of the model attitude angle. Generally, the Mach number control accuracy requirement for the stepped force measurement test reaches ±0.001, and the Mach number control accuracy requirement for the continuous force measurement test reaches ±0.002.

[0006] When the flow field Mach number is greater than 0.7, especially in the transonic stage, the flow field changes dramatically after being disturbed as the model attitude angle changes, especially when the model attitude angle passes "zero" or the model attitude angle is large. When the model attitude angle passes "zero", the overall blockage of the model changes from gradually decreasing to gradually increasing, and the corresponding wind tunnel compressor speed or front chamber total pressure also changes from speed reduction / pressure reduction to speed increase / pressure increase. When the model attitude angle is large, the blockage is greater and the flow separation is more obvious. Therefore, this also poses a higher challenge to flow field control. The current continuous force measurement test method cannot meet the flow field Mach number control accuracy of the same level as the step force measurement test during the entire process of the model attitude angle change after the Mach number is greater than 0.7, especially in the transonic stage, which has an adverse effect on the accuracy of the test data. Summary of the invention

[0007] The present invention aims to solve the problem that in the prior art, when the Mach number is large (Mach number above 0.7, especially in the transonic stage), the flow field Mach number control accuracy cannot reach the same level as the step force measurement test during the entire process of the model attitude angle change, and cannot even meet the Mach number control accuracy requirement of the continuous force measurement test. A wind tunnel continuous force measurement test method is proposed.

[0008] To achieve the above object, the present invention is implemented through the following technical solutions:

[0009] A wind tunnel continuous force measurement test method comprises the following steps:

[0010] S1. Install the wind tunnel test support system, force test balance, and test model in the wind tunnel to complete the test preparation;

[0011] S2. Conduct a windless test, measure the attitude angle of the test model through an angle sensor, obtain the deadweight value of the test model at different attitude angles through a force test balance, and obtain windless test data;

[0012] S3. Start the wind tunnel and adjust the compressor speed so that the Mach number, total pressure and total temperature of the flow field in the model area of ​​the wind tunnel test section reach the target values;

[0013] S4. Conduct wind tests and collect wind tunnel test data for different vehicle tests;

[0014] S5. Based on the wind tunnel test data obtained in step S4, check whether there is test data with a Mach number exceeding the error band, and remove the test data with a Mach number exceeding the error band in the test vehicle;

[0015] S6. According to the windless test data obtained in step S2, the load of the test model under the action of the airflow in the wind tunnel test section is obtained by processing;

[0016] S7. Through the coordinate axis system transformation, the force vector and moment vector in the balance coordinate system are transformed into the force vector and moment vector in the test model body axis system, and the force vector and moment vector in the wind tunnel airflow axis system.

[0017] S8. Through the flow field data collected during the test process, the force vector and moment vector are dimensionless processed to obtain the force coefficient vector and moment coefficient vector in the test model body axis system, and the force coefficient vector and moment coefficient vector in the wind tunnel airflow axis system.

[0018] S9. Taking the angle of attack of the model attitude angle in the test result as the x-axis, and the force coefficient vector and moment coefficient vector in the test model body axis system and the force coefficient vector and moment coefficient vector in the wind tunnel airflow axis system obtained in step S8 as the y-axis respectively, the aerodynamic force variation curve of the test model with the angle of attack and the moment coefficient variation curve with the angle of attack are respectively fitted by the method of locally weighted linear regression.

[0019] Furthermore, the test preparation work in step S1 includes the installation and debugging of test equipment, the installation and calibration of angle sensors, the inspection and debugging of the attitude angle control system, the inspection and debugging of the flow field control system, the surface treatment of the test model, the zero position adjustment of the test model, the measurement of the installation angle between the test model and the force measuring balance, and the inspection and testing of the data acquisition system.

[0020] Furthermore, the specific implementation method of step S4 includes the following steps:

[0021] S4.1. The attitude angle control system is started, and the angle of attack and sideslip angle of the test model are adjusted to the starting state.

[0022] S4.2. The flow field control system closes the loop to adjust the total pressure and Mach number of the test section flow field to the target value.

[0023] S4.3. The data acquisition system starts to collect the flow field data, angle sensor data and the total load of the model measured by the force measuring balance for this test run.

[0024] S4.4. The attitude angle control system controls the test model to start moving towards the next angle of attack target according to the given angle of attack step sequence, and at the same time the flow field control system continuously adjusts the Mach number of the test section flow field to keep it stable within the error band.

[0025] S4.5. The test model judges in real time whether the Mach number of the flow field is within the error band during the movement. When the model attitude angle reaches the target value, if the control accuracy of the flow field Mach number meets the requirements, repeat step S4.4.

[0026] S4.6. If the control accuracy of the flow field Mach number does not meet the requirements, the attitude angle of the test model stops moving, waits for the flow field control system to adjust the flow field Mach number until the control accuracy of the flow field Mach number is stabilized within the error band, and then repeats step S4.4;

[0027] S4.7. After completing all the angle of attack sequences in this train number, the data acquisition system stops collecting, and at the same time, the attitude angle of the test model returns to zero, and the test for this train number ends;

[0028] S4.8. Start the test for the next train number, repeat steps S4.1~S4.7 until all the train numbers of the current test model state are completed, and the test ends. The test train number of the current test model state refers to the test train number without replacing the test model under the current test model state.

[0029] Furthermore, the expression for obtaining the load on the test model under the action of the airflow in the wind tunnel test section in step S6 is:

[0030] ;

[0031] Among them, is the self-weight value of the test model at the i-th attitude angle, is the total load of the test model measured by the force measuring balance under the windy test conditions at the i-th attitude angle , is the load on the test model under the action of the airflow in the wind tunnel test section at the i-th attitude angle.

[0032] Furthermore, the specific implementation method of step S7 includes the following steps:

[0033] S7.1. Set the force measuring balance to the test model coordinate system to satisfy the following relationship:

[0034] ;

[0035] Among them, , , are the pitch, yaw and roll installation angles between the test model and the force measuring balance respectively, obtained during the test preparation in step S1, is the coordinate of the force measuring balance to the test model, is the force measuring balance axis coordinate, is the force measuring balance axis coordinate, is the force measuring balance axis coordinate;

[0036] S7.2. The force vector in the body axis system of the test model and the moment vector in the body axis system of the test model from the force vector of the force-measuring test balance and the moment vector of the force-measuring test balance are converted to obtain the following relationship:

[0037] ;

[0038] wherein, is the force coordinate from the force-measuring test balance to the test model;

[0039] When the centering position of the force-measuring test balance coincides with the moment reference point position of the test model, the following formula is obtained:

[0040] ;

[0041] wherein, is the moment coordinate from the force-measuring test balance to the test model;

[0042] When the centering position of the force-measuring test balance does not coincide with the moment reference point position of the test model, the following formula is obtained:

[0043] ;

[0044] wherein, represents the distances between the moment reference point of the test model and the centering position of the force-measuring test balance in three directions;

[0045] ;

[0046] wherein, is the distance between the moment reference point of the test model and the centering position of the force-measuring test balance in the x direction, is the distance between the moment reference point of the test model and the centering position of the force-measuring test balance in the y direction, is the distance between the moment reference point of the test model and the centering position of the force-measuring test balance in the z direction;

[0047] S7.3. Convert the and in the body axis system of the test model into the force vector in the wind axis system and the moment vector in the wind axis system, and the following relationship is obtained:

[0048] ;

[0049] ;

[0050] wherein, is the Euler rotation matrix of the force coordinate system from the body axis system of the test model to the wind axis system, is the Euler rotation matrix from the body axis system of the test model to the moment coordinate system of the wind axis system;

[0051] The relationship of the Euler rotation matrix from the body axis system of the test model to the wind axis system is as follows:

[0052] ;

[0053] where, is the Euler rotation matrix from the body axis system of the test model to the wind axis system, is the Euler rotation matrix from the wind axis system to the body axis system of the test model, is the angle of attack of the test model axis relative to the oncoming flow of the wind tunnel, is the sideslip angle of the test model axis relative to the oncoming flow of the wind tunnel.

[0054] Furthermore, the specific implementation method of step S8 includes the following steps:

[0055] S8.1. Set the force coefficient of the body axis system of the test model and the moment coefficient of the body axis system of the test model to satisfy the following relationship:

[0056] ;

[0057] ;

[0058] where, S is the reference area of the test model, L is the wingspan of the test model, b represents the reference chord length or mean aerodynamic chord length of the test model's wing, is the dynamic pressure of the wind tunnel flow field;

[0059] ;

[0060] where, is the Mach number of the wind tunnel flow field, is the static pressure of the wind tunnel flow field;

[0061] The expression of the Mach number of the wind tunnel flow field is:

[0062] ;

[0063] ;

[0064] where, is the correction amount of and and are the total pressure and static pressure of the flow field respectively, which are collected by the flow field acquisition system during the test, is the reference Mach number of the wind tunnel plenum chamber;

[0065] The expression of the static pressure in the wind tunnel flow field is as follows:

[0066] ;

[0067] S8.2. Set the force coefficient of the wind axis system and the moment coefficient of the wind axis system to satisfy the following relational expressions:

[0068] ;

[0069] .

[0070] Advantages of the present invention:

[0071] For the continuous force measurement test method in a wind tunnel according to the present invention, the problem of low Mach number control accuracy in continuous measurement tests at relatively large Mach numbers (above Mach 0.7, especially in the transonic stage) is solved.

[0072] For the continuous force measurement test method in a wind tunnel according to the present invention, it fully integrates the advantages of large continuous force measurement data density and high Mach number control accuracy in step tests, and obtains more comprehensive aerodynamic data under the condition of maintaining better Mach number control accuracy, providing more accurate and refined test data support for the development of aircraft. Description of the drawings

[0073] Figure 1 is a flowchart of the continuous force measurement test method in a wind tunnel according to the present invention;

[0074] Figure 2 is a comparison curve between continuous force measurement tests and step force measurement tests;

[0075] Figure 3 is a flowchart of the wind test according to the present invention;

[0076] Figure 4 is a comparison diagram of the Mach number control accuracy obtained by the present invention and the prior art. Detailed implementation manners

[0077] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the drawings and specific implementation manners. It should be understood that the specific implementation manners described herein are only used to explain the present invention and are not used to limit the present invention, that is, the specific implementation manners described are only a part of the implementation manners of the present invention, rather than all of the specific implementation manners. Usually, the components of the specific implementation manners of the present invention described and shown in the drawings here can be arranged and designed in various different configurations, and the present invention can also have other implementation manners.

[0078] Accordingly, 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 claimed invention, but merely represents selected specific embodiments of the present invention. All other specific embodiments obtained by those skilled in the art based on the specific embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0079] To further understand the content, features and effects of the present invention, the following specific embodiments are exemplified and are accompanied by the attached Figure 1 - Attached Figure 4 The details are as follows:

[0080] Example 1:

[0081] A method for continuous wind tunnel force measurement test, comprising the following steps:

[0082] S1. Install a wind tunnel test support system, a force measurement test balance, and a test model in the wind tunnel to complete the test preparation work;

[0083] Further, the test preparation work in step S1 includes the installation and debugging of test equipment, the installation and calibration of angle sensors, the inspection and debugging of the attitude angle control system, the inspection and debugging of the flow field control system, the surface treatment of the test model, the zero position adjustment of the test model, the measurement of the installation angle between the test model and the force measurement test balance, and the inspection and testing of the data acquisition system;

[0084] Further, the calibration of the angle sensor means that after the angle sensor is installed in the model fuselage, an inclination sensor is placed on the model reference platform, the model is adjusted to different attitude angles through the attitude angle control system and the output values of the inclination sensor and the angle sensor are recorded, and finally the conversion relationship between the angle sensor and the inclination sensor is obtained by fitting to complete the calibration of the angle sensor;

[0085] S2. Conduct a windless test, measure the attitude angle of the test model through the angle sensor, obtain the self-weight value of the test model at different attitude angles through the force measurement test balance, and obtain windless test data;

[0086] S3. Start the wind tunnel and adjust the Mach number, total pressure, and total temperature of the flow field in the model area of the wind tunnel test section to the target values by adjusting the compressor speed;

[0087] S4. Conduct a windy test and collect wind tunnel test data for different train runs;

[0088] Further, the specific implementation method of step S4 includes the following steps:

[0089] S4.1. Start the attitude angle control system and adjust the angle of attack and sideslip angle of the test model to the starting state;

[0090] S4.2. The flow field control system closes the loop to adjust the total flow pressure and Mach number of the test section to reach the target value;

[0091] Furthermore, the error band of total pressure is ±100 Pa, and the error band of Mach number is ±0.001;

[0092] S4.3. The data acquisition system starts to collect the flow field data, angle sensor data and total model load measured by the force test balance of this train;

[0093] Furthermore, the flow field data of this train includes the total pressure P 0 , static pressure P ct ;

[0094] S4.4. The attitude angle control system controls the test model to start moving toward the next angle of attack target according to the given angle of attack step sequence, while the flow field control system continuously adjusts the Mach number of the test section flow field to stabilize it within the error band;

[0095] Furthermore, the step angle interval of the angle of attack step sequence is no greater than 0.5°; the error band is ±0.001;

[0096] S4.5. The test model determines in real time during the motion whether the flow field Mach number is within the error band. When the model attitude angle reaches the target value, if the flow field Mach number control accuracy meets the requirements, repeat step S4.4;

[0097] S4.6. If the flow field Mach number control accuracy does not meet the requirements, the test model attitude angle stops moving, and waits for the flow field control system to adjust the flow field Mach number until the flow field Mach number control accuracy is stable within the error band, and then repeats step S4.4;

[0098] S4.7. After completing all the angle of attack sequences in this train, the data acquisition system stops collecting data, and the test model attitude angle returns to zero, and the test of this train ends;

[0099] S4.8. Start the next test train and repeat steps S4.1 to S4.7 until all test trains of the current test model state are completed and the test ends. The test train of the current test model state refers to the test train without changing the test model conditions under the current test model state.

[0100] S5. Based on the wind tunnel test data obtained in step S4, check whether there is test data with a Mach number exceeding the error band, and remove the test data with a Mach number exceeding the error band in the test vehicle;

[0101] S6. According to the windless test data obtained in step S2, the load of the test model under the action of the airflow in the wind tunnel test section is obtained by processing;

[0102] Further, the expression for the load on the test model under the action of the airflow in the wind tunnel test section obtained in step S6 is:

[0103] ;

[0104] where is the self-weight value of the test model at the i-th attitude angle, is the total load of the test model measured by the force-measuring balance under the windy test conditions at the i-th attitude angle , is the load on the test model under the action of the airflow in the wind tunnel test section at the i-th attitude angle;

[0105] S7. Through coordinate system transformation, convert the force vector and moment vector in the balance coordinate system into the force vector and moment vector in the body axis system of the test model and the force vector and moment vector in the wind tunnel airflow axis system;

[0106] Further, the specific implementation method of step S7 includes the following steps:

[0107] S7.1. Set the relationship between the force-measuring balance and the test model coordinate system to satisfy the following formula:

[0108] ;

[0109] where , , are the pitch, yaw, and roll installation angles between the test model and the force-measuring balance, respectively, obtained during the test preparation in step S1, is the coordinate from the force-measuring balance to the test model, is the force-measuring balance axis coordinate, is the force-measuring balance axis coordinate, is the force-measuring balance axis coordinate;

[0110] S7.2. The force vector in the body axis system of the test model and the moment vector in the body axis system of the test model are obtained by converting the force vector of the force-measuring balance and the moment vector of the force-measuring balance, and the following relationship is obtained:

[0111] ;

[0112] where is the force coordinate from the force-measuring balance to the test model;

[0113] When the centering position of the force-measuring test balance coincides with the moment reference point position of the test model, the following equation is obtained:

[0114] ;

[0115] where, is the moment coordinate from the force-measuring test balance to the test model;

[0116] When the centering position of the force-measuring test balance does not coincide with the moment reference point position of the test model, the following equation is obtained:

[0117] ;

[0118] where, represents the distances between the moment reference point of the test model and the centering position of the force-measuring test balance in three directions;

[0119] ;

[0120] ;

[0121] ;

[0122] ;

[0123] ;

[0124] where, is the distance between the moment reference point of the test model and the centering position of the force-measuring test balance in the x direction, is the distance between the moment reference point of the test model and the centering position of the force-measuring test balance in the y direction, is the distance between the moment reference point of the test model and the centering position of the force-measuring test balance in the z direction;

[0125] S7.3. Convert the and in the body-axis system of the test model into the force vector in the wind-axis system and the moment vector in the wind-axis system, and the following relational expressions are obtained:

[0126] ;

[0127] ;

[0128] where, is the Euler rotation matrix of the force coordinate system from the body-axis system to the wind-axis system of the test model, is the Euler rotation matrix of the moment coordinate system from the body-axis system to the wind-axis system of the test model;

[0129] The relational expression of the Euler rotation matrix from the body axis system of the test model to the wind axis system is as follows:

[0130] ;

[0131] Wherein, is the Euler rotation matrix from the body axis system of the test model to the wind axis system, is the Euler rotation matrix from the wind axis system to the body axis system of the test model, is the angle of attack of the axis of the test model relative to the oncoming flow of the wind tunnel, is the sideslip angle of the axis of the test model relative to the oncoming flow of the wind tunnel;

[0132] ;

[0133] .

[0134] S8. Dimensionless processing is performed on the force vector and the moment vector based on the flow field data collected during the test process to obtain the force coefficient vector and the moment coefficient vector in the body axis system of the test model, and the force coefficient vector and the moment coefficient vector in the air flow axis system of the wind tunnel;

[0135] Furthermore, the specific implementation method of step S8 includes the following steps:

[0136] S8.1. Set the force coefficient and the moment coefficient of the body axis system of the test model to satisfy the following relational expressions:

[0137] ;

[0138] ;

[0139] Wherein, S is the reference area of the test model, L is the wingspan of the test model, b represents the reference chord length or the mean aerodynamic chord length of the wing of the test model, is the dynamic pressure of the wind tunnel flow field;

[0140] ;

[0141] ;

[0142] ;

[0143] Wherein, is the Mach number of the wind tunnel flow field, is the static pressure of the wind tunnel flow field;

[0144] The expression of the Mach number of the wind tunnel flow field is:

[0145] ;

[0146] ;

[0147] Among them, is and the correction amount of, which is the specific calibration relationship for each test section of each wind tunnel, and are the total pressure and static pressure of the flow field respectively, which are collected by the flow field acquisition system during the test, is the reference Mach number of the wind tunnel settling chamber;

[0148] The expression of the static pressure of the wind tunnel flow field is:

[0149] ;

[0150] S8.2. Set the force coefficient of the wind axis system and the moment coefficient of the wind axis system to satisfy the following relational expressions:

[0151] ;

[0152] ;

[0153] ;

[0154] .

[0155] S9. Take the angle of attack of the model attitude angle in the test results as the x-axis, and the force coefficient vector and moment coefficient vector under the body axis system of the test model obtained in step S8 and the force coefficient vector and moment coefficient vector under the wind tunnel air flow axis system as the y-axis respectively, and use the method of locally weighted linear regression to fit the curves of the aerodynamic force of the test model changing with the angle of attack and the curve of the moment coefficient changing with the angle of attack respectively.

[0156] It should be noted that relational terms such as "first" and "second" are only used 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 term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising a..." does not exclude the existence of additional identical elements in the process, method, article or device comprising the element.

[0157] Although the present application has been described above with reference to specific embodiments, various modifications can be made thereto and components thereof can be replaced with equivalents without departing from the scope of the present application. In particular, as long as there is no structural conflict, the features in the specific embodiments disclosed in the present application can be combined with each other in any manner, and the reason for not exhaustively describing the situations of these combinations in this specification is only to save space and 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 wind tunnel continuous force measurement test method, characterized in that: The steps include: S1. Install the wind tunnel test support system, force test balance, and test model in the wind tunnel to complete the test preparation; S2. Conduct a windless test, measure the attitude angle of the test model through an angle sensor, obtain the deadweight value of the test model at different attitude angles through a force test balance, and obtain windless test data; S3. Start the wind tunnel and adjust the compressor speed so that the Mach number, total pressure and total temperature of the flow field in the model area of ​​the wind tunnel test section reach the target values; S4. Conduct wind tests and collect wind tunnel test data for different vehicle tests; S5. Based on the wind tunnel test data obtained in step S4, check whether there is test data with Mach number exceeding the error band, and remove the test data with Mach number exceeding the error band in the test vehicle; S6. Based on the windless test data obtained in step S2, the load of the test model under the action of the airflow in the wind tunnel test section is obtained by processing; The expression of the load of the test model under the action of the airflow in the wind tunnel test section obtained in step S6 is: N bi =N ei -N gi Among them, N gi is the weight of the test model at the i-th attitude angle, N ei is the total load N of the test model at the i-th attitude angle measured by the force test balance under wind test conditions ei , N bi is the load on the test model under the action of the airflow in the wind tunnel test section at the i-th attitude angle; S7. By means of coordinate axis conversion, the force vector and moment vector in the balance coordinate system are converted into the force vector and moment vector in the test model body axis system and the force vector and moment vector in the wind tunnel airflow axis system; S8. Perform dimensionless processing on the force vector and the moment vector through the flow field data collected during the test process to obtain the force coefficient vector and the moment coefficient vector under the axis system of the test model body and the force coefficient vector and the moment coefficient vector under the axis system of the wind tunnel airflow; S9. With the angle of attack of the model attitude angle in the test results as the x-axis, the force coefficient vector and the moment coefficient vector under the test model body axis system and the force coefficient vector and the moment coefficient vector under the wind tunnel airflow axis system obtained in step S8 as the y-axis, respectively, the aerodynamic force curve varying with the angle of attack and the moment coefficient curve varying with the angle of attack of the test model are fitted by the local weighted linear regression method.

2. A wind tunnel continuous force measurement test method according to claim 1, characterized in that: The test preparation work in step S1 includes the installation and debugging of the test equipment, the installation and calibration of the angle sensor, the inspection and debugging of the attitude angle control system, the inspection and debugging of the flow field control system, the surface treatment of the test model, the zero position adjustment of the test model, the measurement of the installation angle of the test model and the force test balance, and the inspection and testing of the data acquisition system.

3. A wind tunnel continuous force measurement test method according to claim 2, characterized in that: The specific implementation method of step S4 includes the following steps: S4.

1. Start the attitude angle control system and adjust the test model's angle of attack and sideslip angle to the initial state; S4.

2. The flow field control system closes the loop to adjust the total flow pressure and Mach number of the test section to achieve the target value; S4.

3. The data acquisition system starts to collect the flow field data, angle sensor data and total model load measured by the force test balance of this train; S4.

4. The attitude angle control system controls the test model to start moving to the next angle of attack target according to the given angle of attack step sequence, while the flow field control system continuously adjusts the Mach number of the test section flow field to stabilize it within the error band; S4.

5. During the movement, the test model determines in real time whether the flow field Mach number is within the error band. When the model attitude angle reaches the target value, if the flow field Mach number control accuracy meets the requirements, repeat step S4.4; S4.

6. If the flow field Mach number control accuracy does not meet the requirements, the test model attitude angle stops moving, and waits for the flow field control system to adjust the flow field Mach number until the flow field Mach number control accuracy is stable within the error band, and then repeats step S4.4; S4.

7. After completing all the angle of attack sequences in this train, the data acquisition system stops collecting data, and the test model attitude angle returns to zero, and the test of this train ends; S4.

8. Start the next test train and repeat steps S4.1 to S4.7 until all test trains in the current test model state are completed and the test ends. The test train in the current test model state refers to the test train in the current test model state without changing the test model conditions.

4. A wind tunnel continuous force measurement test method according to claim 3, characterized in that: The specific implementation method of step S7 includes the following steps: S7.

1. Set the force test balance to the test model coordinate system to satisfy the following relationship: R mb =R X (f mb )R Z (i mb )R Y (ψ mb ) Among them, θ mb , mb ,φ mb are the pitch, yaw and roll installation angles between the test model and the force test balance, which are obtained during the test preparation in step S1, R mb R is the coordinate of the force test balance to the test model, X is the X-axis coordinate of the force test balance, R Z is the Z-axis coordinate of the force test balance, R Y is the Y-axis coordinate of the force test balance; S7.

2. Force vectors in the test model body axis system [N m ] and the moment vector [M m ]The force vector of the force test balance [N b ] and the moment vector of the force test balance [M b ] is converted to obtain the following relationship: in, The force coordinates from the force test balance to the test model; When the centering position of the force test balance coincides with the position of the test model torque reference point, the following formula is obtained: in, is the moment coordinate from the force test balance to the test model; When the centering position of the force test balance does not coincide with the position of the test model torque reference point, the following formula is obtained: Among them, ΔL represents the distance between the test model torque reference point and the centering position of the force test balance in three directions; Among them, L x L is the distance between the test model torque reference point and the centering position of the force test balance in the x direction. y To represent the distance between the test model torque reference point and the centering position of the force test balance in the y direction, L z It represents the distance between the test model torque reference point and the centering position of the force test balance in the z direction; S7.

3. Set the [N m ] and [M m ] is converted to the force vector [N w ] and the moment vector [M w ], we get the following relationship: in, is the Euler rotation matrix of the force coordinate system from the test model body axis system to the wind axis system, is the Euler rotation matrix of the moment coordinate system from the test model body axis system to the wind axis system; The relationship between the Euler rotation matrix of the test model body axis system and the wind axis system is as follows: Among them, R wm is the Euler rotation matrix from the test model body axis to the wind axis, R mw is the Euler rotation matrix from the wind axis to the test model body axis, α is the attack angle of the test model axis relative to the wind tunnel flow, and β is the sideslip angle of the test model axis relative to the wind tunnel flow.

5. A wind tunnel continuous force measurement test method according to claim 4, characterized in that: The specific implementation method of step S8 includes the following steps: S8.

1. Set the force coefficients of the test model axis system [C Nm ] and the moment coefficient of the test model axis system [C Mm ] satisfies the following relationship: Where S is the reference area of ​​the test model, L is the wing span of the test model, b represents the reference chord length or average aerodynamic chord length of the wing of the test model, and q is the dynamic pressure of the wind tunnel flow field; q=0.7*P cp *M 2 Where M is the Mach number of the wind tunnel flow field, P cp is the static pressure of the wind tunnel flow field; The expression of the Mach number of the wind tunnel flow field is: M=M CT +ΔM Where ΔM is M CT The correction amount with M is the specific calibration relationship of each wind tunnel test section, P0 and P ct are the total pressure and static pressure of the flow field, respectively, which are collected by the flow field acquisition system during the test. CT is the reference Mach number of the wind tunnel chamber; The expression of static pressure in wind tunnel flow field is: S8.

2. Set the force coefficients for the wind axis [C Nw ] and the moment coefficient of the wind axis [C Mw ] satisfies the following relationship:

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