Method for simulating test of servo dummy tail of 1-meter wind tunnel support interference test

Abstract

The application provides a 1-meter wind tunnel support interference test follow-up false tail support simulation test method, and belongs to the technical field of wind tunnel test of aviation aerodynamics. The purpose is to solve the problems of easy deviation and interference of the post-root false tail support simulation under large wind load, difficult simulation of large sideslip, and the problem of non-real simulation of the relative position of the false tail support to the model caused by the limitation of the position compensation mechanism of the domestic 1-meter high-speed wind tunnel, which affects the test results. The application comprises the following steps: S1. determining the relative length of the false tail support simulation; S2. selecting a false tail support small balance according to the relative length determined in S1, designing a false tail support small balance adapter and a false tail support rod, reducing the weight of the model, and manufacturing the model; and S3. performing the wind tunnel test according to the two-step method of the test mapping. The application adopts the front-root false tail support force measuring small balance connection, realizes the real-time synchronous movement of the false tail support and the model, avoids the relative position deviation, structural interference and difficult simulation of large sideslip, and reduces the measurement error of the support interference.

Description

Technical Field

[0001] This invention belongs to the field of aerodynamic wind tunnel testing technology, and particularly relates to a method for simulating the servo pseudo tail support in wind tunnel support interference tests of 1-meter scale. Background Technology

[0002] When force measurement models are tested in a wind tunnel, any form of support will interfere with the wind tunnel test results. In particular, conventional tail support tests often require local magnification of the tail of the model to connect to the balance, which leads to tail distortion and interference from the tail strut. This not only affects the prediction of cruise efficiency, focal position, and trim angle of attack, but also interferes with the prediction of rudder effect. The data must be corrected during use.

[0003] Currently, wind tunnel testing remains the most important means of evaluating support interference. High-speed wind tunnel tail support interference tests mainly employ a two-step experimental imaging method, using an auxiliary support belt and a dummy tail support without a tail support to obtain the effects of tail distortion and tail support rod interference. The auxiliary support belt dummy tail support configuration often uses a single-balance support with a "post-rooting" connection method. This involves a main balance connected to the model to measure its aerodynamic forces, while the rear end of the dummy tail support is fixed and connected to the downstream support mechanism, and the front end extends into the model's tail cavity without being connected to the model. The main balance measurement results do not include the dummy tail support's aerodynamic forces. This testing method suffers from the problem that the relative position between the model and the dummy tail support is prone to shift and interference under high wind loads, affecting the simulation effect of the dummy tail support and even leading to balance measurement distortion. Furthermore, this method of simulating dummy tail supports presents difficulties in simulating large sideslip.

[0004] Currently, in domestic 2-meter-class wind tunnels, to address the problems encountered in simulating "post-rooted" pseudo tail branches, a drive mechanism is typically added at the downstream connection end of the pseudo tail branch for position compensation, adjusting the relative position of the pseudo tail branch and the model in real time. However, in domestic 1-meter-class high-speed wind tunnels, due to limitations in support rod size, model, and support blockage requirements, it is difficult to use the method of installing a position compensation mechanism downstream of the pseudo tail branch for pseudo tail branch simulation. The simulation of the pseudo tail branch's relative position to the model is not realistic, affecting the results of support interference tests.

[0005] In summary, there is an urgent need to design a method that can solve the problems of easy deviation and interference in the simulation of "post-rooted" pseudo tails under high wind loads, the difficulty in simulating large sideslip, and the inability to use position compensation mechanisms in domestic 1-meter-class high-speed wind tunnels, which leads to unrealistic simulation of the pseudo tail relative to the model position and affects the test results. This method can reduce test errors and improve the accuracy of test results. Summary of the Invention

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

[0007] In view of this, in order to solve the problems of easy deviation and interference in the simulation of "post-rooted" pseudo tails under high wind loads, difficulty in simulating large sideslip, and the inability to use position compensation mechanisms in domestic 1-meter-class high-speed wind tunnels due to limitations, which leads to unrealistic simulation of the pseudo tail relative to the model position and affects the test results, this invention provides a follow-up pseudo tail simulation test method for 1-meter-class wind tunnel support interference test.

[0008] Solution: A simulation test method for a servo-driven pseudo-tailbone in a 1-meter-scale wind tunnel support interference test, specifically including the following steps:

[0009] S1. Determine the relative length of the simulated tail branch;

[0010] S2. Based on the simulated relative length of the dummy tail support determined in S1, a six-component lever balance is selected as the dummy tail support balance. Then, the adapter and dummy tail support lever of the dummy tail support balance are designed, the weight of the digital model is reduced, and finally the model is manufactured.

[0011] S3. Assemble a servo-driven pseudo tail support simulation device for a 1-meter-scale wind tunnel support interference test, and conduct wind tunnel tests according to the "two-step method" of the test image.

[0012] Furthermore, S1 specifically includes the following steps:

[0013] S11. Using CFD simulation, the longitudinal aerodynamic coefficient difference between the model with tail support and the model with partial simulated tail support was compared; the near-field relative position of the dummy tail support and the model was accurately simulated, and the optimal simulated relative length of the dummy tail support under the experimental M (Mach) number was obtained. The simulated relative length of the dummy tail support was expressed as the ratio L / D of the simulated length of the dummy tail support rod divided by the equivalent diameter D of the model tail.

[0014] S12. Based on the CFD simulation results in step 11, when the drag coefficient difference ΔCx remains approximately constant as the simulated relative length of the dummy tail increases and is less than the accuracy index of the high-speed wind tunnel force measurement test specified in the national military standard GJB 1061-91, then the simulation of the relative length of the dummy tail is considered sufficient; among which, the critical value of the relative length of the dummy tail is different for different Mach numbers, with a subsonic critical value of ≈6 and a supersonic critical value of ≈2.

[0015] Furthermore, S2 specifically includes the following steps:

[0016] S21. Based on the simulated relative length of the pseudotail within different M (Mach) number ranges determined in S1, the aerodynamic coefficient of the pseudotail is extracted, which serves as the basis for selecting the main balance and the pseudotail balance in the subsequent process.

[0017] S22. Design of the dummy tail support balance: Based on the aerodynamic force of the dummy tail support determined in S21, the dummy tail support balance is designed as a conventional six-component rod balance. The diameter design of the dummy tail support balance ensures that it does not interfere with the dummy tail support within the test load range.

[0018] S23. Design of the dummy tail support balance adapter: The fixed end of the dummy tail support balance adapter is connected to the rear end face of the model steel sleeve through a flange, and the free end protrudes out of the model tail cavity and is connected to the dummy tail support balance through a cone. The dummy tail support balance adapter is designed as a straight rod; and the axis of the dummy tail support balance adapter coincides with the axis of the model steel sleeve. The interior of the dummy tail support balance adapter is hollow.

[0019] S24. Design of the dummy tail support: The dummy tail support adopts a segmented design. The front half is a fixed section, which is connected to the dummy tail support balance through a rear cone fit. The front end of the dummy tail support extends into the tail cavity of the model by no less than 25mm. The rear half is the rectification section. The relative length of the dummy tail support is changed and adjusted according to the different Mach number ranges determined in S12. Long support is used for subsonic and transonic speeds, and short support is used for supersonic speeds. The dummy tail support adopts a lightweight design.

[0020] S25. Determine the connection structure of the dummy tail support: The dummy tail support balance is inverted relative to model 1. The cone is connected to the model through the dummy tail support balance adapter. The front cone is connected to the dummy tail support rod. The cable of the dummy tail support balance passes through the inner cavity of the dummy tail support balance adapter, passes through the fuselage, and is led out to the cable tray of the belly support.

[0021] S26. Stiffness and strength verification: Evaluate the overall stiffness of the web support rod with dummy tail support, evaluate the stiffness of the dummy tail support adapter with dummy tail support and dummy tail support balance, ensure that the natural frequency of the model and support system avoids the peak frequency of low-frequency noise in the wind tunnel, and finally manufacture the relevant test pieces.

[0022] S27. Calibration of the dummy tail balance: Before the test, perform static calibration of the balance and calibrate the elastic angle of the dummy tail balance with the adapter.

[0023] Furthermore, the inner cavity of the pseudo tail support small balance adapter described in S23 is treated to prevent air leakage.

[0024] Furthermore, the centering point of the dummy tail support balance described in S25 is located at the center of mass of the dummy tail support rod.

[0025] Furthermore, S3 specifically includes the following steps:

[0026] S31. The model is mounted on the abdominal support rod via the main balance and the abdominal support rod cone sleeve. The dummy tail support balance is mounted on the model steel sleeve via the dummy tail support balance adapter. The cables of the main balance and the dummy tail support balance are led to the cable routing cavity of the abdominal support rod through the cable routing hole inside the machine body. The tail cavity and the abdominal cavity of the model are sealed to prevent air leakage.

[0027] S32. Measure the initial installation relative spatial position relationship of the balance centering point of the main balance and the pseudo tail support balance relative to the model torque reference point, and the initial installation angle relative to the model body axis system;

[0028] S33. Perform wind tunnel test according to the force measurement high-speed wind tunnel test method: The main balance measurement results include the model aerodynamic force, the pseudo tail aerodynamic force, the interference of the belly branch on the model, and the interference of the pseudo tail on the model; the pseudo tail small balance measures the aerodynamic force acting on the pseudo tail.

[0029] S34. Data processing: Rotate the force system of the force measurement results of the main balance and the pseudo tail support balance respectively, and then translate the force system to convert the measurement values ​​of each balance to be consistent with the axis system of the model body;

[0030] S35. Obtaining the influence of tail support interference: After combining the measurement results of the main balance and the pseudo tail support balance, the experimental results are consistent with the main balance measurement values ​​of the traditional "post-rooting" pseudo tail support simulation method. Then, combined with the experimental state of the ventral branch without pseudo tail support, the final tail support interference is obtained according to the experimental image "two-step method".

[0031] Furthermore, the specific steps of S34 data processing are as follows:

[0032] The model's body coordinate system is set to O. m -X m Y m Z m The model torque reference center is (x m y m z m The model's attitude angle is (α) m ,β m γ m The balance calibration center is (x) i y i z i ), attitude angle is (α) i ,β i γ i ); where i=1 represents the main balance; i=2 represents the dummy tail balance; due to the installation position deviation between the two balances and the model; in addition, when there is wind load, the dummy tail balance and the dummy tail balance adapter undergo elastic deformation, and the position of the dummy tail balance relative to the model will change.

[0033] The relative positions and angles between the model force balance and the model moment reference center are as follows:

[0034] ……………………………………(1)

[0035] ……………………………………(2)

[0036] In the formula, m represents the model. For the model force balance and model torque reference center Relative position of direction For the model force balance and model torque reference center Relative position of direction For the model force balance and model torque reference center Relative position of direction For the model force balance and model torque reference center relative angle of direction For the model force balance and model torque reference center relative angle of direction For the model force balance and model torque reference center Direction relative angle;

[0037] The force system is rotated based on the force measurements from the main balance and the dummy tail balance, as shown in the following formula:

[0038] = …………………………………(3)

[0039] = ……………………………………(4)

[0040] In the formula, Main Balance and False Tail Balance Direction measurement results, Main Balance and False Tail Balance Directional force measurement results, Main Balance and False Tail Balance Direction measurement results, The rolling torque measurement results of the main balance and the dummy tail balance. Measurement results of yaw moment of the main balance and the dummy tail balance The results of pitching moment measurements of the main balance and the dummy tail balance. Main Balance and False Tail Balance The value after orientation rotation transformation Main Balance and False Tail Balance The value after orientation rotation transformation Main Balance and False Tail Balance The value after orientation rotation transformation The values ​​after rotational transformation of the rolling torque of the main balance and the dummy tail balance. The values ​​of the yaw moment after rotation transformation of the main balance and the dummy tail balance. The values ​​of the pitching torque after rotation transformation of the main balance and the pseudo tail balance;

[0041] The coordinate transformation matrix is ​​calculated using the following formula:

[0042] =

[0043] =

[0044] = ……………………………………………………………………………………………(5)

[0045] In the formula, This is the transformation matrix from the balance axis system to the model body axis system. Let X be the transformation matrix about the X-axis. Let Y be the transformation matrix around the Y-axis. This is the transformation matrix around the Z-axis;

[0046] Finally, the force system is translated to move the measured values ​​of the balance after rotational transformation to the model's moment reference center (x). m y m z m ), and the resultant force value is obtained through linear superposition ( , , , , , );

[0047] ……………………………………(6)

[0048] …………………(7)

[0049] In the formula, The resultant axial force value is obtained by linear superposition. The resultant normal force value is obtained by linear superposition. The resultant lateral force value is obtained by linear superposition. The resultant rolling torque value is obtained by linear superposition. The resultant yaw moment value is obtained by linear superposition. This represents the combined pitching moment value obtained through linear superposition.

[0050] The present invention has the following advantages over the prior art:

[0051] 1. This invention uses a "pre-rooted" pseudo tail support force balance connection to achieve real-time synchronous movement between the pseudo tail support and the model, avoiding relative position offset, structural interference and large side slip simulation difficulties, and reducing support interference measurement errors;

[0052] 2. This invention utilizes the coordinated operation of two balances: the main balance measures the aerodynamic force of the main body of the model, while the small balance measures the aerodynamic force of the dummy tail. This allows for the measurement of high-precision aerodynamic force of the dummy tail while simultaneously obtaining support interference.

[0053] 3. This invention provides the requirements for the simulated relative length of the dummy tail during support interference tests, with a critical value of approximately 6 for subsonic transonic speeds and approximately 2 for supersonic speeds. This provides a clear basis for the setting of dummy tails in wind tunnel tests and improves the accuracy of test results. Attached Figure Description

[0054] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0055] Figure 1 A schematic diagram of the servo pseudo tail support simulation test device for wind tunnel support interference test of 1-meter scale;

[0056] Figure 2 A diagram showing the positional relationship between the model and the tail support;

[0057] Figure 3 A diagram showing the positional relationship between the model and some of the tail supports;

[0058] Figure 4 The results are CFD calculations of the relative length of the pseudotail branch simulation.

[0059] In the diagram: 1-Model, 2-Main balance, 3-Abdominal support rod cone sleeve, 4-Abdominal support rod, 5-Model steel sleeve, 6-Dummy tail support small balance adapter, 7-Dummy tail support small balance, 8-Dummy tail support rod, 9-Model tail cavity, 10-Model abdominal cavity. Detailed Implementation

[0060] To make the technical solutions and advantages of the embodiments of the present invention clearer, the exemplary embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0061] Examples, References Figure 1-3 This embodiment describes a method for simulating the motion of a dummy tail branch in a 1-meter-scale wind tunnel support interference test, which specifically includes the following steps:

[0062] S1. Determine the relative length of the simulated tail branch;

[0063] S2. Based on the simulated relative length of the dummy tail support determined in S1, a six-component lever balance is selected as the dummy tail support balance 7. Then, the dummy tail support balance adapter 6 and the dummy tail support lever 8 are designed, and the weight of the digital model is reduced. Finally, the model is manufactured.

[0064] S3. Assemble a servo-driven pseudo tail support simulation device for a 1-meter-scale wind tunnel support interference test, and conduct wind tunnel tests according to the "two-step method" of the test image.

[0065] Furthermore, S1 specifically includes the following steps:

[0066] S11. Using CFD simulation, the longitudinal aerodynamic coefficient difference between Model 1 with tail support and Model 1 with partial simulated tail support was compared; the near-field relative position of the dummy tail support and Model 1 was accurately simulated, and the optimal simulated relative length of the dummy tail support under the experimental M number was obtained. The simulated relative length of the dummy tail support was expressed as the ratio L / D of the simulated length L of the dummy tail support rod 8 divided by the equivalent diameter D of the tail of Model 1.

[0067] S12. Based on the CFD simulation results in step 11, when the drag coefficient difference ΔCx remains approximately constant as the simulated relative length of the dummy tail increases and is less than the accuracy index of the high-speed wind tunnel force measurement test specified in the national military standard GJB 1061-91, then the simulation of the relative length of the dummy tail is considered sufficient; among which, the critical value of the relative length of the dummy tail is different for different Mach numbers, with a subsonic critical value of ≈6 and a supersonic critical value of ≈2.

[0068] Furthermore, S2 specifically includes the following steps:

[0069] S21. Based on the simulated relative length of the pseudotail within different M number ranges determined in S1, the aerodynamic coefficient of the pseudotail is extracted, which serves as the basis for selecting the main balance 2 and the pseudotail small balance 7.

[0070] S22. Design of the dummy tail support balance 7: Based on the aerodynamic force of the dummy tail support determined in S21, and referring to the GJB 2244A-2011 wind tunnel strain balance specification, the dummy tail support balance 7 is designed as a conventional six-component rod balance. The diameter design of the dummy tail support balance 7 ensures that it does not interfere with the dummy tail support within the test load range.

[0071] S23. Design of the dummy tail support balance adapter 6: The fixed end of the dummy tail support balance adapter 6 is connected to the rear end face of the model steel sleeve 5 through a flange, and the free end protrudes out of the model tail cavity 9 and is connected to the dummy tail support balance 7 through a cone. The dummy tail support balance adapter 6 is designed as a straight rod; and the axis of the dummy tail support balance adapter 6 coincides with the axis of the model steel sleeve 5. The interior of the dummy tail support balance adapter 6 is hollow to facilitate wiring.

[0072] S24. Design of the dummy tail support rod 8: The dummy tail support rod 8 adopts a segmented design. The front half is a fixed section, which is connected to the dummy tail support balance 7 through a rear cone fit. The front end of the dummy tail support rod 8 extends into the tail cavity 9 of the model by no less than 25mm. The rear half is the rectification section. The relative length of the dummy tail support is changed and adjusted according to the different Mach number ranges determined in S12. Long support rods are used for subsonic and transonic speeds, and short support rods are used for supersonic speeds. The purpose is to reduce the axial force output of the dummy tail support balance 7. In order to improve the overall support stiffness, the dummy tail support rod 8 adopts a lightweight design.

[0073] S25. Determine the connection structure of the dummy tail support: The dummy tail support balance 7 is inverted relative to the model 1. The cone is connected to the model 1 through the dummy tail support balance adapter 6. The front cone is connected to the dummy tail support rod 8. The cable of the dummy tail support balance 7 passes through the fuselage through the inner cavity of the dummy tail support balance adapter 6 and is led out to the cable routing groove of the belly support.

[0074] S26. Perform stiffness and strength verification according to the requirements of GJB 569A-2012 High-speed wind tunnel model design criteria: evaluate the overall stiffness of the abdominal support rod 4 with dummy tail support, evaluate the stiffness of the dummy tail support adapter 6 with dummy tail support and dummy tail support balance 7, ensure that the natural frequency of model 1 and support system avoids the peak frequency of low-frequency noise in the wind tunnel, and finally manufacture relevant test pieces.

[0075] S27. Calibration of the dummy tail support balance 7: Before the test, perform static calibration of the balance according to the requirements of GJB 2244A-2011 Wind Tunnel Strain Balance Specification, and perform elastic angle calibration of the dummy tail support balance 7 with the dummy tail support balance adapter 6.

[0076] Furthermore, the inner cavity of the pseudo tail support small balance adapter 6 described in S23 is treated to prevent cross-ventilation, thus avoiding cross-ventilation between the model tail cavity 9 and the model abdominal cavity 10.

[0077] Furthermore, the centering point of the dummy tail support balance 7 described in S25 is located at the center of mass of the dummy tail support rod 8.

[0078] Furthermore, S3 specifically includes the following steps:

[0079] S31. Model 1 is mounted on the abdominal support rod 4 via the main balance 2 and the abdominal support rod cone sleeve 3. The dummy tail support balance 7 is mounted on the model steel sleeve 5 via the dummy tail support balance adapter 6. The cables of the main balance 2 and the dummy tail support balance 7 are led to the cable routing cavity of the abdominal support rod 4 through the cable routing hole inside the machine body. The tail cavity 9 of the model and the abdominal cavity 10 of the model are sealed to prevent air leakage.

[0080] S32. Measure the initial installation relative spatial position relationship of the balance centering point of the main balance 2 and the dummy tail support balance 7 relative to the torque reference point of model 1, and the initial installation angle relative to the body axis system of model 1;

[0081] S33. Perform wind tunnel test according to the force measurement high-speed wind tunnel test method: The measurement results of the main balance 2 include the aerodynamic force of model 1, the aerodynamic force of the dummy tail branch, the interference of the belly branch on model 1, and the interference of the dummy tail branch on model 1; the dummy tail branch small balance 7 measures the aerodynamic force acting on the dummy tail branch.

[0082] S34. Data processing: Rotate the force system of the force measurement results of the main balance 2 and the pseudo tail support balance 7 respectively, and then translate the force system to convert the measurement values ​​of each balance to be consistent with the body axis of model 1.

[0083] S35. Obtaining the influence of tail support interference: After combining the measurement results of the main balance 2 and the pseudo tail support balance 7, the experimental results are consistent with the main balance measurement values ​​of the traditional "post-rooting" pseudo tail support simulation method. Then, combined with the experimental state of the ventral branch without pseudo tail support, the final tail support interference is obtained according to the experimental image "two-step method".

[0084] Furthermore, the specific steps of S34 data processing are as follows:

[0085] Model 1's volume coordinate system is set to O. m -X m Y m Z m The torque reference center of Model 1 is (x m y m z m Model 1 attitude angle is (α) m ,β m γ m The balance calibration center is (x) i y i z i ), attitude angle is (α) i ,β i γ i); where i = 1 represents the main balance 2; i = 2 represents the dummy tail support balance 7; due to the installation position deviation between the two balances and model 1; in addition, when there is wind load, the dummy tail support balance 7 and the dummy tail support balance adapter 6 undergo elastic deformation, and the position of the dummy tail support balance 7 relative to model 1 will change.

[0086] The relative positions and angles between the Model 1 force balance and the Model 1 torque reference center are as follows:

[0087] ……………………………………(1)

[0088] ……………………………………(2)

[0089] In the formula, m represents model 1. For the force balance of Model 1 and the torque reference center of Model 1 Relative position of direction For the force balance of Model 1 and the torque reference center of Model 1 Relative position of direction For the force balance of Model 1 and the torque reference center of Model 1 Relative position of direction For the force balance of Model 1 and the torque reference center of Model 1 relative angle of direction For the force balance of Model 1 and the torque reference center of Model 1 relative angle of direction For the force balance of Model 1 and the torque reference center of Model 1 Direction relative angle;

[0090] The force system is rotated based on the force measurements obtained from the main balance 2 and the pseudo tail balance 7, as shown in the following formula:

[0091] = …………………………………(3)

[0092] = ……………………………………(4)

[0093] In the formula, Main Balance 2 and False Tail Balance 7 Direction measurement results, Main Balance 2 and False Tail Balance 7 Direction measurement results, Main Balance 2 and False Tail Balance 7 Direction measurement results, The rolling torque measurement results of the main balance 2 and the dummy tail balance 7 Measurement results of yaw moment of main balance 2 and pseudo tail balance 7 The results of pitching moment measurements for the main balance 2 and the pseudo tail balance 7. Main Balance 2 and False Tail Balance 7 The value after orientation rotation transformation Main Balance 2 and False Tail Balance 7 The value after orientation rotation transformation Main Balance 2 and False Tail Balance 7 The value after orientation rotation transformation The values ​​of the rolling torque after rotation transformation of the main balance 2 and the pseudo tail balance 7. The values ​​of the yaw moment after rotation transformation of the main balance 2 and the pseudo tail balance 7. The values ​​of the pitching moment after rotation transformation of the main balance 2 and the pseudo tail balance 7;

[0094] The coordinate transformation matrix is ​​calculated using the following formula:

[0095] =

[0096] =

[0097] = ……………………………………………………………………………………………(5)

[0098] In the formula, This is the transformation matrix from the balance axis system to the model body axis system. Let X be the transformation matrix about the X-axis. Let Y be the transformation matrix around the Y-axis. This is the transformation matrix around the Z-axis;

[0099] Finally, the force system is translated to move the measured values ​​of the balance after rotational transformation to the model's moment reference center (x). m y m z m ), and the resultant force value is obtained through linear superposition ( , , , , , );

[0100] ……………………………………(6)

[0101] …………………(7)

[0102] In the formula, The resultant axial force value is obtained by linear superposition. The resultant normal force value is obtained by linear superposition. The resultant lateral force value is obtained by linear superposition. The resultant rolling torque value is obtained by linear superposition. The resultant yaw moment value is obtained by linear superposition. This represents the combined pitching moment value obtained through linear superposition.

[0103] This invention employs a "pre-rooted" dummy tail support force balance connection to achieve real-time synchronous movement between the dummy tail support and the model, avoiding relative position offset, structural interference, and difficulties in simulating large sideslip, and reducing measurement errors in support interference. It also provides requirements for the simulated relative length of the dummy tail support during support interference tests, with a subsonic transonic critical value of ≈6 and a supersonic critical value of ≈2, providing a clear basis for dummy tail support settings in wind tunnel tests and improving the accuracy of test results.

[0104] This invention utilizes the collaborative operation of two balances: the main balance measures the aerodynamic force of the main body of the model, while the small balance measures the aerodynamic force of the pseudo-tail support. This allows for the measurement of the high-precision aerodynamic force of the pseudo-tail support while simultaneously obtaining support interference.

[0105] Although the invention has been described with reference to a limited number of embodiments, those skilled in the art will understand from the foregoing description that other embodiments are conceivable within the scope of the invention described herein. Furthermore, it should be noted that the language used in this specification has been chosen primarily for readability and instructional purposes, and not for the purpose of interpreting or limiting the subject matter of the 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 invention is illustrative and not restrictive, and the scope of the invention is defined by the appended claims.

Claims

A method for simulating the motion of a dummy tail support in a 1.1-meter-scale wind tunnel support interference test, characterized in that: Specifically, the following steps are included: S1. Determine the relative length of the simulated tail branch; S1 specifically includes the following steps: S11. Using CFD simulation, the longitudinal aerodynamic coefficient difference between model (1) with tail support and model (1) with partial simulated tail support was compared; the near-field relative position of the dummy tail support and model (1) was accurately simulated, and the optimal simulated relative length of the dummy tail support under the experimental M number was obtained. The simulated relative length of the dummy tail support was expressed as the ratio L / D of the simulated length L of the dummy tail support rod (8) divided by the equivalent diameter D of the tail of model (1). S12. Based on the CFD simulation results in step 11, when the drag coefficient difference ΔCx remains approximately constant as the simulated relative length of the dummy tail increases and is less than the accuracy index of the high-speed wind tunnel force measurement test specified in the national military standard GJB 1061-91, then the simulation of the relative length of the dummy tail is considered sufficient; among which, the critical value of the relative length of the dummy tail is different for different Mach numbers, with a subsonic critical value ≈6 and a supersonic critical value ≈2. S2. Based on the simulated relative length of the dummy tail support determined in S1, a six-component lever balance is selected as the dummy tail support balance (7). Then, the dummy tail support balance adapter (6) and dummy tail support lever (8) are designed. The weight of the digital model is reduced, and finally the model is manufactured. S2 specifically includes the following steps: S21. Based on the simulated relative length of the pseudotail within different M number ranges determined by S1, the aerodynamic coefficient of the pseudotail is extracted, which serves as the basis for selecting the subsequent main balance (2) and pseudotail balance (7). S22. Design of the pseudo tail support balance (7): Based on the pseudo tail support aerodynamic force determined in S21, the pseudo tail support balance (7) is designed as a conventional six-component rod balance. The diameter design of the pseudo tail support balance (7) ensures that it does not interfere with the pseudo tail support within the test load range. S23. Design of the dummy tail support balance adapter (6): The fixed end of the dummy tail support balance adapter (6) is connected to the rear end face of the model steel sleeve (5) through a flange, and the free end protrudes out of the model tail cavity (9) and is connected to the dummy tail support balance (7) through a cone. The dummy tail support balance adapter (6) is designed as a straight rod. The axis of the dummy tail support balance adapter (6) coincides with the axis of the model steel sleeve (5). The interior of the dummy tail support balance adapter (6) is hollow. S24. Design of the dummy tail support rod (8): The dummy tail support rod (8) adopts a segmented design. The front half is a fixed section, which is connected to the dummy tail support balance (7) through a rear cone fit. The front end of the dummy tail support rod (8) extends into the tail cavity (9) of the model by no less than 25mm. The rear half is a rectification section. The relative length of the dummy tail support is changed and adjusted according to the different M number ranges determined in S12. Long support rods are used for subsonic and transonic speeds, and short support rods are used for supersonic speeds. The dummy tail support rod (8) adopts a lightweight design. S25. Determine the connection structure of the dummy tail support: The dummy tail support balance (7) is inverted relative to the model (1), the cone is connected to the model (1) through the dummy tail support balance adapter (6), the front cone is connected to the dummy tail support rod (8), and the cable of the dummy tail support balance (7) passes through the fuselage through the inner cavity of the dummy tail support balance adapter (6) and is led out to the cable tray of the belly support. S26. Perform stiffness and strength verification: evaluate the overall stiffness of the abdominal support rod (4) with the dummy tail support, evaluate the stiffness of the dummy tail support adapter (6) with the dummy tail support and the dummy tail support balance (7), satisfy the natural frequency of the model (1) and the support system to avoid the peak frequency of low-frequency noise in the wind tunnel, and finally manufacture the relevant test pieces. S27. Calibration of the dummy tail balance (7): Before the test, perform static calibration of the balance and calibrate the elastic angle of the dummy tail balance (7) with the adapter (6). S3. Assemble a servo-driven pseudo tail support simulation device for a 1-meter-scale wind tunnel support interference test, and conduct wind tunnel tests according to the "two-step method" of the test image.

2. The method for simulating the servo-driven pseudo-tailbone in a 1-meter-scale wind tunnel support interference test according to claim 1, characterized in that, The inner cavity of the pseudo tail support small balance adapter (6) in S23 is treated to prevent air leakage.

3. The method for simulating the servo-driven pseudo-tailbone in a 1-meter-scale wind tunnel support interference test according to claim 2, characterized in that, The centering point of the dummy tail support balance (7) in S25 is located at the center of mass of the dummy tail support rod (8).

4. The method for simulating the servo-driven pseudo-tailbone in a 1-meter-scale wind tunnel support interference test according to claim 3, characterized in that, S3 specifically includes the following steps: S31. The model (1) is mounted on the abdominal support rod (4) through the main balance (2) and the abdominal support rod cone sleeve (3), and the dummy tail support balance (7) is mounted on the model steel sleeve (5) through the dummy tail support balance adapter (6); the cables of the main balance (2) and the dummy tail support balance (7) are led to the cable routing cavity of the abdominal support rod (4) through the cable routing hole inside the body; the tail cavity (9) of the model and the abdominal cavity (10) of the model are sealed. S32. Measure the initial installation relative spatial position relationship of the torque reference point of the main balance (2) and the dummy tail balance (7) relative model (1) and the initial installation angle of the body axis system of the relative model (1); S33. Perform wind tunnel test according to the force measurement high-speed wind tunnel test method: The main balance (2) measures the aerodynamic force of model (1), the aerodynamic force of the pseudo tail branch, the interference of the belly branch on model (1) and the interference of the pseudo tail branch on model (1); the pseudo tail branch small balance (7) measures the aerodynamic force acting on the pseudo tail branch; S34. Data processing: Rotate the force system of the force measurement results of the main balance (2) and the pseudo tail support balance (7) respectively, and then translate the force system to convert the measured values ​​of each balance to be consistent with the body axis of the model (1); S35. Obtain the tail support interference effect: After the measurement results of the main balance (2) and the pseudo tail support balance (7) are combined, the test results are consistent with the main balance measurement value of the traditional "post-rooting" pseudo tail support simulation method. Then, combined with the test state of the ventral branch without pseudo tail support, the final tail support interference is obtained according to the "two-step method" of the test image.

5. The method for simulating the servo-driven pseudo-tailbone in a 1-meter-scale wind tunnel support interference test according to claim 4, characterized in that, The specific steps of the S34 data processing are as follows: Model (1) The body coordinate system is set to O. m -X m Y m Z m The torque reference center of model (1) is (x) m y m z m The attitude angle of model (1) is (α) m ,β m γ m The balance calibration center is (x) i y i z i ), attitude angle is (α) i ,β i γ i ); where i = 1 represents the main balance (2); i = 2 represents the pseudo tail support balance (7); due to the installation position deviation between the two balances and the model (1); in addition, when there is wind load, the pseudo tail support balance (7) and the pseudo tail support balance adapter (6) undergo elastic deformation, and the position of the pseudo tail support balance (7) relative to the model (1) will change; The relative positions and angles between the force balance of model (1) and the torque reference center of model (1) are as follows: ……………………………………(1) ……………………………………(2) In the formula, m represents model (1). For the force balance of model (1) and the torque reference center of model (1) Relative position of direction For the force balance of model (1) and the torque reference center of model (1) Relative position of direction For the force balance of model (1) and the torque reference center of model (1) Relative position of direction For the force balance of model (1) and the torque reference center of model (1) relative angle of direction For the force balance of model (1) and the torque reference center of model (1) relative angle of direction For the force balance of model (1) and the torque reference center of model (1) Direction relative angle; The force system is rotated based on the force measurement results of the main balance (2) and the pseudo tail balance (7), as shown in the following formula: = …………………………………(3) = ……………………………………(4) In the formula, The main balance (2) and the pseudo tail balance (7) Direction measurement results The main balance (2) and the pseudo tail balance (7) Direction measurement results The main balance (2) and the pseudo tail balance (7) Direction measurement results The rolling torque measurement results of the main balance (2) and the pseudo tail balance (7) are as follows: Yaw moment measurement results of the main balance (2) and the pseudo tail balance (7), The results of pitching moment measurements using the main balance (2) and the pseudo tail balance (7) are as follows: The main balance (2) and the pseudo tail balance (7) The value after orientation rotation transformation The main balance (2) and the pseudo tail balance (7) The value after orientation rotation transformation The main balance (2) and the pseudo tail balance (7) The value after orientation rotation transformation The values ​​of the rolling torque after rotation transformation of the main balance (2) and the pseudo tail balance (7) are as follows: The values ​​of the yaw moment after rotation transformation of the main balance (2) and the pseudo tail balance (7) The values ​​of pitch torque after rotation transformation of the main balance (2) and the pseudo tail balance (7); The coordinate transformation matrix is ​​calculated using the following formula: = ； ； In the formula, This is the transformation matrix from the balance axis system to the model body axis system. Let X be the transformation matrix about the X-axis. The transformation matrix around the Y-axis, This is the transformation matrix around the Z-axis; Finally, the force system is translated to move the measured values ​​of the balance after rotational transformation to the model's moment reference center (x). m y m z m ), and the resultant force value is obtained through linear superposition ( , , , , , ); ……………………………………(6) …………………(7) In the formula, The resultant axial force value is obtained by linear superposition. The resultant normal force value is obtained by linear superposition. The resultant rolling torque value is obtained by linear superposition. The resultant yaw moment value is obtained by linear superposition. This represents the combined pitching moment value obtained through linear superposition.

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