A low-speed wind tunnel support interference test method based on a mechanical arm support mode

Abstract

A low-speed wind tunnel support interference test method based on a mechanical arm support mode belongs to the wind tunnel support interference test field.The present application comprises S1, the model adopts a positive installation back support strut without a web support strut and an auxiliary support to measure the model aerodynamic force;S2, the model adopts a positive installation web support strut without a back support strut but with an auxiliary support to measure the model aerodynamic force;S3, the model adopts a positive installation web support strut without a back support strut and an auxiliary support to measure the model aerodynamic force;S4, the model adopts a positive installation web support strut with a back support strut and an auxiliary support to measure the model aerodynamic force;S5, according to S1-S4, the model adopts a web support and a back support strut to obtain the support interference quantity.The present application aims to solve the switching test of the web support and the back support, that is, to quickly obtain the web support and the back support interference quantity, to simplify the test steps, to greatly reduce the test operation and data processing difficulty, and to improve the test efficiency.

Description

TECHNICAL FIELD

[0001] The application relates to a low-speed wind tunnel support interference test method based on a mechanical arm support mode and belongs to the wind tunnel support interference test field. BACKGROUND

[0002] A model is supported by a support in a wind tunnel test section to measure aerodynamic force. The existence of the support changes the flow field around the model, thereby causing changes in the model measurement value, which is support interference. Due to different model test purposes, model shapes and test wind speed ranges, model support types are various, but they all cause certain interference to the model, and the support interference of some supports can reach several times of the true value of model aerodynamic force. Therefore, generally, wind tunnel test data must be corrected for support interference.

[0003] The mechanical arm support type is widely used in large low-speed wind tunnels because the mechanical arm support type is driven by a hydraulic system, has a large test angle range, has strong system load capacity and can adopt a moving belt floor to reduce the boundary layer effect in ground effect test. For large aspect ratio aircraft model aerodynamic force measurement test, according to different test purposes, an inner type balance abdomen support and a back support can be respectively used. However, due to the existence of the support, the aerodynamic force felt by the model is still interfered, and the straight support affects the measurement accuracy of test data.

[0004] Therefore, it is urgent to provide a low-speed wind tunnel support interference test method based on a mechanical arm support mode to solve the above technical problems. SUMMARY

[0005] The research and development purpose of the application is to solve the problem of switching test of abdomen support and back support, that is, to quickly obtain the interference of abdomen support and back support. In the following, a brief summary of the application is given to provide a basic understanding of some aspects of the application. It should be understood that this summary is not an exhaustive summary of the application. It is not intended to determine the key or important parts of the application, nor to limit the scope of the application.

[0006] The technical scheme of the application is as follows:

[0007] A low-speed wind tunnel support interference test method based on a mechanical arm support mode, comprising:

[0008] S1, a model is measured for aerodynamic force in a mode of a back support strut without an abdomen support strut and an auxiliary support, that is, the model is fixedly installed on a mechanical arm through a back support strut to obtain a first component F1 of air force measured by a balance in a test;

[0009] S2, the model is aerodynamically measured by using a positive-mounted abdominal support rod without a back support rod but with an auxiliary support. That is, the model is fixedly installed on the robotic arm by the abdominal support rod, and an auxiliary support is installed on the abdominal support rod to obtain the second component of aerodynamic force F2 measured by the balance in the experiment.

[0010] S3, the model adopts the method of using the upright abdominal support rod without the back support rod and auxiliary support to measure the aerodynamic force of the model. That is, the model is fixedly installed on the robotic arm by the abdominal support rod to obtain the third component of aerodynamic force F3 measured by the balance in the experiment.

[0011] S4, the model was aerodynamically measured using a positive-mounted abdominal support rod with a back support rod and an auxiliary support, and the fourth component of aerodynamic force F4 was obtained by the balance during the experiment.

[0012] S5, Based on S1-S4, the interference ΔF of the abdominal support strut is obtained when the model is used in the formal force measurement test with abdominal support. zj1 ,as follows:

[0013] ΔF zj1 =F4-F1-(F3-F2)

[0014] Based on S2-S4, the interference ΔF of the back support rod is calculated when the model is used in the formal force measurement test with abdominal support. zj2 ,as follows:

[0015] ΔF zj2 =F4-F2-(F3-F2).

[0016] Preferably, the two ends of the back support rod are the ID segment and the ICD segment, respectively. The model is connected to the front end of the balance, and the ID segment is fixedly connected to the rear end of the balance.

[0017] Preferably, the two ends of the abdominal support rod are segment IV and segment ICV, respectively. The model is connected to the front end of the balance, and segment IV is fixedly connected to the rear end of the balance.

[0018] Preferably, in S1, the ICD segment of the back support rod is fixedly connected to the ISD segment of the robotic arm, and the first aerodynamic component F1 measured by the balance during the experiment is:

[0019] F1 = F M +F ID +F ICD +F ISD

[0020] In the formula: F M Aerodynamics for a standalone model; F ID F represents the amount of aerodynamic interference of the back support rod on the model; ICD F represents the amount of aerodynamic interference of the ICD section of the back support rod on the model;ISD This represents the amount of aerodynamic interference of the robotic arm's ISD segment on the model.

[0021] Preferably, in S2, the ICV segment of the abdominal support rod is fixedly connected to the ISV segment of the robotic arm, and an auxiliary bracket is installed on the ICV segment of the abdominal support rod. The second aerodynamic component F2 measured by the balance during the experiment is:

[0022] F2 = F M +F IV +F ICV +F ISV

[0023] In the formula: F IV F represents the aerodynamic interference of section IV of the strut on the model; ICV F represents the aerodynamic interference of the ICV section of the strut on the model; ISV This represents the amount of aerodynamic interference of the robotic arm's ISV segment on the model.

[0024] Preferably, in step S4, the ICV segment of the abdominal support rod is fixedly connected to the ISV segment of the robotic arm, and the third aerodynamic component F3 measured by the balance during the experiment is:

[0025] F3 = F M +F IV +F ICV +F ISV +F IT

[0026] In the formula: F IT The amount of aerodynamic interference of the IT section of the auxiliary support on the model.

[0027] Preferably, in S3, the ICV segment of the abdominal support rod is fixedly connected to the ISV segment of the robotic arm, and both ends of the auxiliary support are fixedly connected to the ICV segment of the abdominal support rod and the ICD segment of the back support rod, respectively. A wake region (ICW) for the back support rod is provided on the rear side of the ICD segment of the back support rod. The fourth aerodynamic component F4 measured by the balance during the experiment is:

[0028] F4 = F M +F IV +F ICV +F ISV +F ID +F ICD +F ICW +F IT

[0029] In the formula: F ICW This represents the amount of aerodynamic interference of the back support strut wake region ICW on the model.

[0030] The present invention has the following beneficial effects:

[0031] 1. The present invention uses a switching test between abdominal support rods and back support rods to quickly obtain the interference of abdominal and back support brackets, simplifying the test steps, greatly reducing the difficulty of test operation and data processing, and improving test efficiency;

[0032] 2. This invention can obtain more comprehensive stent interference amounts in the near and far fields of the model, improving the accuracy of stent interference subtraction in experimental data. Attached Figure Description

[0033] Figure 1 This is a diagram illustrating the usage state of the model of the present invention, which uses a positive back support rod without a belly support rod and auxiliary bracket for aerodynamic force measurement.

[0034] Figure 2 This is a diagram illustrating the usage state of the model of the present invention, which uses a positive-mounted abdominal support rod without a back support rod but with an auxiliary bracket for aerodynamic measurement.

[0035] Figure 3 This is a diagram illustrating the usage state of the model of the present invention, which uses a positive-mounted abdominal support rod without a back support rod and auxiliary bracket for aerodynamic force measurement.

[0036] Figure 4 This is a diagram illustrating the usage state of the model of the present invention, which uses a positive-mounted abdominal support rod with a back support rod and an auxiliary support for aerodynamic measurement.

[0037] In the diagram, 1-back support rod, 2-abdominal support rod, 3-auxiliary support, 4-model, 5-robotic arm. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0039] The connections mentioned in this invention are divided into fixed connections and detachable connections. Fixed connections, also known as non-detachable connections, include but are not limited to conventional fixed connection methods such as folded connections, riveted connections, adhesive connections, and welded connections. Detachable connections include but are not limited to conventional disassembly methods such as threaded connections, snap-fit ​​connections, pin connections, and hinged connections. When a specific connection method is not explicitly defined, it is assumed that at least one existing connection method can always be found to achieve the function, and those skilled in the art can choose according to their needs. For example, a welded connection can be chosen for fixed connections, and a hinged connection can be chosen for detachable connections.

[0040] Specific implementation method one: CombiningFigures 1-4 This embodiment describes a low-speed wind tunnel support interference test method based on a robotic arm support. Model 4 is connected to the front end of a balance, and the rear end of the balance is connected to either the back support rod 1 or the abdominal support rod 2. The balance calibration center is aligned as closely as possible with the model's torque reference center. The back support rod 1 or the abdominal support rod 2 does not directly contact model 4. Specifically, this includes:

[0041] S1, Model 4 uses the upright back support rod 1 without the abdominal support rod 2 and auxiliary bracket 3 to measure the aerodynamic force of the model. That is, Model 4 is fixedly installed on the robotic arm 5 through the back support rod 1 to obtain the first component of aerodynamic force F1 measured by the balance in the experiment.

[0042] The two ends of the back support rod 1 are the ID segment and the ICD segment, respectively, and the ID segment is fixedly connected to the model 4.

[0043] The two ends of the abdominal support rod 2 are segment IV and segment ICV, respectively, and segment IV is fixedly connected to model 4.

[0044] In S1, the ICD segment of the back support rod 1 is fixedly connected to the ISD segment of the robotic arm 5. The first aerodynamic component F1 measured by the balance during the experiment is:

[0045] F1 = F M +F ID +F ICD +F ISD (1)

[0046] In the formula: F M Aerodynamics for a standalone model; F ID F represents the aerodynamic interference of the back support rod 1 on model 4. ICD F represents the amount of aerodynamic interference of the ICD section of the back support rod 1 on model 4; ISD The interference amount of the ISD segment of the robotic arm 5 on the aerodynamics of the model 4. (The interference amount of each segment is only an intermediate process quantity. Finally, the support interference amount when the model is supported on the abdomen and back can be obtained by formula (5) and formula (6) respectively.

[0047] S2, Model 4 uses the upright abdominal support rod 2 without the back support rod 1 but with the auxiliary bracket 3 to measure the aerodynamic force of the model. That is, Model 4 is fixedly installed on the robotic arm 5 by the abdominal support rod 2, and the auxiliary bracket 3 is installed on the abdominal support rod 2 to obtain the second component of aerodynamic force F2 measured by the balance in the experiment.

[0048] In S2, the ICV segment of the abdominal support rod 2 is fixedly connected to the ISV segment of the robotic arm 5, and an auxiliary bracket 3 is installed on the ICV segment of the abdominal support rod 2. The second aerodynamic component F2 measured by the balance during the experiment is:

[0049] F2 = F M +F IV +F ICV +F ISV (2)

[0050] In the formula: F IV F represents the amount of aerodynamic interference of section IV of the ventral strut 2 on model 4; ICV F represents the amount of aerodynamic interference of the ICV section of the ventral strut 2 on model 4; ISV The amount of interference of the ISV segment of robotic arm 5 on the aerodynamics of model 4.

[0051] S3, Model 4 uses the upright abdominal support rod 2 without the back support rod 1 and auxiliary bracket 3 to measure the aerodynamic force of the model. That is, Model 4 is fixedly installed on the robotic arm 5 through the abdominal support rod 2 to obtain the third component of aerodynamic force F3 measured by the balance in the experiment.

[0052] In S3, the ICV segment of the abdominal support rod 2 is fixedly connected to the ISV segment of the robotic arm 5. The third aerodynamic component F3 measured by the balance during the experiment is:

[0053] F3 = F M +F IV +F ICV +F ISV +F IT (3)

[0054] In the formula: F IT The amount of interference of the IT segment of the auxiliary support 3 on the aerodynamics of model 4.

[0055] S4, Model 4 uses the method of positive abdominal support rod 2 with back support rod 1 and auxiliary support 3 to measure the aerodynamic force of the model and obtain the fourth component of aerodynamic force F4 measured by the balance in the experiment;

[0056] In S4, the ICV segment of the abdominal support rod 2 is fixedly connected to the ISV segment of the robotic arm 5. The two ends of the auxiliary support 3 are fixedly connected to the ICV segment of the abdominal support rod 2 and the ICD segment of the back support rod 1, respectively. The wake region ICW of the back support rod 1 is located on the rear side of the ICD segment. The fourth aerodynamic component F4 measured by the balance during the experiment is:

[0057] F4 = F M +F IV +F ICV +F ISV +F ID +F ICD +F ICW +F IT (4)

[0058] In the formula: F ICWThe amount of interference of the wake region ICW of the back support rod 1 on the aerodynamics of Model 4.

[0059] S5, based on S1-S4, the interference ΔF of the abdominal support rod 2 is obtained when Model 4 adopts the abdominal support formal force measurement test. zj1 Substituting formulas (1), (2), (3), and (4) into formula (5), we get the following:

[0060] ΔF zj1 =F4-F1-(F3-F2) (5)

[0061] Based on S2-S4, the interference ΔF of the support rod 1 in the formal force measurement test of Model 4 with back support is obtained. zj2 Substituting formulas (2), (3), and (4) into formula (6), we get the following:

[0062] ΔF zj2 =F4-F2-(F3-F2) (6).

[0063] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be permuted and combined. Those skilled in the art can exhaust all possibilities based on the mathematical knowledge of permutation and combination. Therefore, the present invention will not describe the technical solutions after permutation and combination one by one, but it should be understood that the technical solutions after permutation and combination have been disclosed by the present invention.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A low-speed wind tunnel support interference test method based on a mechanical arm support mode, characterized in that, Comprise: S1, the model (4) is fixedly installed on the mechanical arm (5) through the back support strut (1), and the first component F1 of the air dynamic force measured by the balance in the test is obtained, that is, the model (4) is measured by the model aerodynamic force in the mode of positive installation of back support strut (1) without abdominal support strut (2) and auxiliary support (3); S2, the model (4) is fixedly installed on the mechanical arm (5) through the abdominal support strut (2), and the second component F2 of the air dynamic force measured by the balance in the test is obtained, that is, the model (4) is measured by the model aerodynamic force in the mode of positive installation of abdominal support strut (2) without back support strut (1) but with auxiliary support (3); S3, the model (4) is fixedly installed on the mechanical arm (5) through the abdominal support strut (2), and the third component F3 of the air dynamic force measured by the balance in the test is obtained, that is, the model (4) is measured by the model aerodynamic force in the mode of positive installation of abdominal support strut (2) without back support strut (1) and auxiliary support (3); S4, the model (4) is measured by the model aerodynamic force in the mode of positive installation of abdominal support strut (2) with back support strut (1) and auxiliary support (3), and the fourth component F4 of the air dynamic force measured by the balance in the test is obtained; S5, according to S1-S4, derive the model (4) that the support interference amount ΔF of the abdominal support pole (2) when the abdominal support formal force test is adopted zj1 As follows: ΔF zj1 = F4 - F1 - (F3 - F2) (5) According to S2-S4, the model (4) is derived, which shows that the interference amount ΔF of the back support strut (1) when the back support is used in the official measurement of the force test zj2 As follows: ΔF zj2 = F4 - F2 - (F3 - F2) (6).

2. The low-speed wind tunnel support interference test method based on a mechanical arm support mode according to claim 1, characterized in that: The two ends of the back support strut (1) are ID section and ICD section respectively, the model (4) is connected with the front end of the balance, and the ID section is fixedly connected with the rear end of the balance.

3. The low-speed wind tunnel support interference test method based on a mechanical arm support mode according to claim 2, characterized in that: The two ends of the abdominal support strut (2) are IV section and ICV section respectively, the model (4) is connected with the front end of the balance, and the IV section is fixedly connected with the rear end of the balance.

4. The low-speed wind tunnel support interference test method based on a mechanical arm support mode according to claim 3, characterized in that: In the S1, the ICD section of the back support strut (1) is fixedly connected with the ISD section of the mechanical arm (5), and the first component F1 of the air dynamic force measured by the balance in the test is: F1 = F M +F ID +F ICD +F ISD (1) where: F M is the aerodynamic force of the individual model; F ID is the interference of the back-up strut (1) on the aerodynamic force of the model (4); F ICD is the interference of the ICD section of the back-up strut (1) on the aerodynamic force of the model (4); F ISD is the interference of the ISD section of the robot arm (5) on the aerodynamic force of the model (4).

5. The low-speed wind tunnel support interference test method based on a mechanical arm support mode according to claim 4, characterized in that: In the S2, the ICV section of the abdominal support strut (2) is fixedly connected with the ISV section of the mechanical arm (5), and the second component F2 of the air dynamic force measured by the balance in the test is: F2 = F M +F IV +F ICV +F ISV (2) where: F IV F is the amount of interference of the IV section of the brace strut (2) on the aerodynamics of the model (4); ICV F is the amount of interference of the ICV section of the brace strut (2) on the aerodynamics of the model (4); ISV F is the amount of interference of the ISV section of the mechanical arm (5) on the aerodynamics of the model (4).

6. The low-speed wind tunnel support interference test method based on a mechanical arm support mode according to claim 5, characterized in that: In the S3, the ICV section of the abdominal support strut (2) is fixedly connected with the ISV section of the mechanical arm (5), and the third component F3 of the air dynamic force measured by the balance in the test is: F3 = F M +F IV +F ICV +F ISV +F IT (3) In the formula: F IT is the amount of interference of the IT section of the auxiliary support (3) with the aerodynamics of the model (4).

7. The low-speed wind tunnel support interference test method based on a mechanical arm support mode according to claim 6, characterized in that: In the S4, the ICV section of the abdominal support strut (2) is fixedly connected with the ISV section of the mechanical arm (5), the two ends of the auxiliary support (3) are fixedly connected with the ICV section of the abdominal support strut (2) and the ICD section of the back support strut (1) respectively, the rear side of the ICD section of the back support strut (1) is provided with the wake area ICW of the back support strut (1), and the fourth component F4 of the air dynamic force measured by the balance in the test is: F4 = F M +F IV +F ICV +F ISV +F ID +F ICD +F ICW +F IT (4) where: F ICW is the amount of interference of the wake region ICW of the backstay mast (1) with the aerodynamic force of the model (4).

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