Low-speed wind tunnel support interference test method based on mechanical arm supporting mode

Abstract

The invention discloses a low-speed wind tunnel support interference test method based on a mechanical arm supporting mode, and belongs to the field of wind tunnel support interference tests. The method comprises the steps that S1, model aerodynamic force measurement is carried out on a model in the mode that a back supporting rod is positively installed without a belly supporting rod and an auxiliary support; s2, carrying out model aerodynamic force measurement on the model by adopting a mode that a front belly supporting rod is not provided with a back supporting rod but is provided with an auxiliary bracket; s3, carrying out model aerodynamic force measurement on the model by adopting a mode of positively installing a belly supporting rod without a back supporting rod and an auxiliary bracket; s4, carrying out model aerodynamic force measurement on the model by adopting a mode of positively installing a belly supporting rod with a back supporting rod and an auxiliary bracket; and S5, according to the steps S1 to S4, obtaining the support interference variable of the model adopting an abdomen support and a back support strut. The research and development aim of the invention is to solve the problem that the interference variable of the abdominal support and the back support can be quickly obtained by adopting a switching test of the abdominal support and the back support, so that the test steps are simplified, the test operation and data processing difficulty is greatly reduced, and the test efficiency is improved.

Description

Technical Field

[0001] The invention relates to a low-speed wind tunnel support interference test method based on a mechanical arm support mode, and belongs to the field of wind tunnel support interference tests. Background Art

[0002] The model is tested in a wind tunnel by supporting it with a bracket in the wind tunnel test section for aerodynamic measurement. Due to the existence of the bracket, the flow field around the model changes, which leads to changes in the model measurement value. This is the bracket interference. Due to the different purposes of model tests, model shapes and test wind speed ranges, there are many types of model brackets, but they will all cause certain interference to the model. Some bracket interference can reach several times the true value of the model's aerodynamic force. Therefore, in general, wind tunnel test data must be corrected for bracket interference.

[0003] The manipulator support type is widely used in large low-speed wind tunnels because it is driven by a hydraulic system, has a large test angle range, a strong system load-bearing capacity, and can use a moving belt floor to reduce the boundary layer effect of the ground effect test when conducting ground effect tests. For aerodynamic measurement tests of large aspect ratio aircraft models, two types of internal balance belly support and back support can be used according to different test purposes. However, due to the presence of the support, it will still interfere with the aerodynamic force felt by the model, and the straight support affects the measurement accuracy of the test data.

[0004] Therefore, it is urgent to propose a low-speed wind tunnel bracket interference test method based on mechanical arm support to solve the above technical problems. Summary of the invention

[0005] The purpose of the present invention is to solve the problem of quickly obtaining the interference amount of the abdominal support bracket and the back support bracket by switching the abdominal support bracket and the back support bracket. A brief overview of the present invention is given below to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to determine the key or important parts of the present invention, nor is it intended to limit the scope of the present invention.

[0006] The technical solution of the present invention:

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

[0008] S1, the model is measured for aerodynamic force by using a normal back support rod without a belly support rod and an auxiliary support, that is, the model is fixed on the mechanical arm by the back support rod, and the first component of aerodynamic force F measured by the balance in the test is obtained. 1 ;

[0009] S2, the model is measured for aerodynamic force by using a normal belly support rod without a back support rod but with an auxiliary support, that is, the model is fixed on the mechanical arm through the belly support rod, and the belly support rod is equipped with an auxiliary support, and the second component of aerodynamic force F measured by the balance in the test is obtained 2 ;

[0010] S3, the model is measured for aerodynamic force by using the upright belly support rod without the back support rod and auxiliary bracket, that is, the model is fixed on the mechanical arm through the belly support rod, and the third component of aerodynamic force F measured by the balance in the test is obtained. 3 ;

[0011] S4, the model adopts the method of upright abdominal support rod with back support rod and auxiliary support to measure the model aerodynamic force, and obtains the fourth component of aerodynamic force F measured by the balance in the test 4 ;

[0012] S5, according to S1-S4, it is concluded that when the model is subjected to the formal force test using the abdominal support, the support interference value of the abdominal support rod is ΔF zj1 ,as follows:

[0013] ΔF zj1 =F 4 -F 1 -(F 3 -F 2 )

[0014] According to S2-S4, when the model is formally tested with abdominal support, the support interference ΔF of the back support rod is obtained. zj2 ,as follows:

[0015] ΔF zj2 =F 4 -F 2 -(F 3 -F 2 ).

[0016] Preferably, the two ends of the back-supporting rod are respectively an ID segment and an ICD segment, 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 section of the back support rod is fixedly connected to the ISD section of the mechanical arm, and the first component of the aerodynamic force F measured by the balance in the test 1 for:

[0019] F 1 =F M +F ID +FICD +F ISD

[0020] Where: F M is the aerodynamic force of the individual model; F ID F is the interference of the back support rod on the aerodynamic force of the model; ICD F is the interference of the ICD section of the back support rod on the aerodynamics of the model; ISD is the interference amount of the ISD segment of the robot arm on the aerodynamic force of the model.

[0021] Preferably, in S2, the ICV section of the belly support rod is fixedly connected to the ISV section of the mechanical arm, and an auxiliary bracket is installed on the ICV section of the belly support rod. The second component of the aerodynamic force F measured by the balance in the test 2 for:

[0022] F 2 =F M +F IV +F ICV +F ISV

[0023] Where: F IV is the interference of the IV section of the abdominal support rod on the aerodynamics of the model; F ICV is the interference of the ICV section of the abdominal support rod on the aerodynamics of the model; F ISV is the interference amount of the ISV section of the robot arm on the aerodynamic force of the model.

[0024] Preferably, in S4, the ICV section of the abdominal support rod is fixedly connected to the ISV section of the mechanical arm, and the third component of the aerodynamic force F measured by the balance during the test 3 for:

[0025] F 3 =F M +F IV +F ICV +F ISV +F IT

[0026] Where: F IT is the interference amount of the IT section of the auxiliary bracket on the aerodynamic force of the model.

[0027] Preferably: in said S3, the ICV section of the abdominal support rod is fixedly connected to the ISV section of the mechanical arm, the two ends of the auxiliary bracket are respectively fixedly connected to the ICV section of the abdominal support rod and the ICD section of the back support rod, and the back support rod wake area ICW is arranged at the rear side of the ICD section of the back support rod. The fourth component of aerodynamic force F measured by the balance in the test 4 for:

[0028] F 4 =FM +F IV +F ICV +F ISV +F ID +F ICD +F ICW +F IT

[0029] Where: F ICW is the interference amount of the ICW in the wake area of ​​the back support rod on the aerodynamics of the model.

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

[0031] 1. The switching test of the abdominal support rod and the back support rod of the present invention can quickly obtain the interference amount of the abdominal support and the back support bracket, simplify the test steps, greatly reduce the difficulty of test operation and data processing, and improve the test efficiency;

[0032] 2. The present invention can obtain more comprehensive near-field and far-field bracket interference values ​​of the model, thereby improving the bracket interference subtraction accuracy of the test data. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a diagram showing the use state of the model of the present invention in which the model aerodynamic force is measured by adopting a method of installing a back support rod without an abdominal support rod and an auxiliary support;

[0034] Figure 2 The figure is a diagram showing the use of the model of the present invention in which the model is subjected to aerodynamic measurement by adopting a normal abdominal support rod without a back support rod but with an auxiliary support;

[0035] Figure 3 It is a diagram showing the use state of the model of the present invention in which the model aerodynamic force measurement is performed by adopting a normal abdominal support rod without a back support rod and an auxiliary support;

[0036] Figure 4 The figure is a diagram showing the use of the model of the present invention in which the model is subjected to aerodynamic measurement by adopting a method of a normal abdominal support rod with a back support rod and an auxiliary support;

[0037] In the figure, 1-back support rod, 2-abdominal support rod, 3-auxiliary support, 4-model, 5-mechanical arm. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0039] The connection mentioned in the present invention is divided into fixed connection and detachable connection. The fixed connection is a non-detachable connection including but not limited to conventional fixed connection methods such as folding connection, rivet connection, bonding connection and welding connection. The detachable connection includes but not limited to conventional detachable methods such as threaded connection, snap connection, pin connection and hinge connection. When the specific connection method is not clearly defined, it is assumed that at least one connection method can always be found in the existing connection methods to achieve the function. Those skilled in the art can choose according to their needs. For example: a fixed connection is selected as a welding connection, and a detachable connection is selected as a hinge connection.

[0040] Specific implementation method 1: Combination Figure 1-Figure 4 The present embodiment is described. The present embodiment is a low-speed wind tunnel support interference test method based on a mechanical arm support method. The model 4 is connected to the front end of the balance, and the rear end of the balance is connected to the back support rod 1 or the abdominal support rod 2. The balance calibration center is as close as possible to the model moment reference center. The back support rod 1 or the abdominal support rod 2 is not in direct contact with the model 4. Specifically, it includes:

[0041] S1, the aerodynamic force of the model 4 is measured by using the upright back support rod 1 without the abdominal support rod 2 and the auxiliary support 3, that is, the model 4 is fixedly installed on the mechanical arm 5 through the back support rod 1, and the first component of the aerodynamic force F measured by the balance in the test is obtained. 1 ;

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

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

[0044] In S1, the ICD section of the back support rod 1 is fixedly connected to the ISD section of the mechanical arm 5. The first component of the aerodynamic force F measured by the balance in the test 1 for:

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

[0046] Where: F M is the aerodynamic force of the individual model; F ID is the interference of the back support rod 1 on the aerodynamic force of model 4; F ICD is the interference of the ICD section of the back support rod 1 on the aerodynamic force of the model 4; F ISDis the interference amount of the ISD segment of the robot 5 on the aerodynamics of the model 4. (The interference amount of each segment is only the intermediate process amount. Finally, the bracket interference amount when the model is supported by the abdomen and back can be obtained by formula (5) and formula (6) respectively.

[0047] S2, the model 4 adopts the method of installing the belly support rod 2 without the back support rod 1 but with the auxiliary support 3 to measure the model aerodynamic force, that is, the model 4 is fixedly installed on the mechanical arm 5 through the belly support rod 2, and the auxiliary support 3 is installed on the belly support rod 2, and the second component of the aerodynamic force F measured by the balance in the test is obtained 2 ;

[0048] In S2, the ICV section of the belly support rod 2 is fixedly connected to the ISV section of the mechanical arm 5, and an auxiliary bracket 3 is installed on the ICV section of the belly support rod 2. The second component of the aerodynamic force F measured by the balance in the test 2 for:

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

[0050] Where: F IV F is the interference amount of the IV section of the belly support rod 2 on the aerodynamic force of the model 4; ICV is the interference amount of the ICV section of the abdominal support rod 2 on the aerodynamic force of the model 4; F ISV is the interference amount of the ISV segment of the robot 5 on the aerodynamic force of the model 4.

[0051] S3, the aerodynamic force of the model 4 is measured by using the upright belly support rod 2 without the back support rod 1 and the auxiliary support 3, that is, the model 4 is fixedly installed on the mechanical arm 5 through the belly support rod 2, and the third component of the aerodynamic force F measured by the balance in the test is obtained. 3 ;

[0052] In S3, the ICV section of the abdominal support rod 2 is fixedly connected to the ISV section of the mechanical arm 5. The third component of the aerodynamic force F measured by the balance in the test 3 for:

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

[0054] Where: F IT is the interference amount of the IT section of the auxiliary bracket 3 on the aerodynamic force of the model 4.

[0055] S4, model 4 uses the upright abdominal support rod 2 with back support rod 1 and auxiliary support 3 to measure the model aerodynamic force, and obtains the fourth component of aerodynamic force F measured by the balance in the test 4 ;

[0056] In the S4, the ICV section of the abdominal support rod 2 is fixedly connected to the ISV section of the mechanical arm 5, and the two ends of the auxiliary bracket 3 are fixedly connected to the ICV section of the abdominal support rod 2 and the ICD section of the back support rod 1, respectively. The back support rod 1 wake area ICW is arranged at the rear side of the ICD section of the back support rod 1. The fourth component of aerodynamic force F measured by the balance in the test 4 for:

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

[0058] Where: F ICW is the interference amount of ICW in the wake area of ​​back support rod 1 on the aerodynamic force of model 4.

[0059] S5, according to S1-S4, it is obtained that when the model 4 adopts the abdominal support formal force test, the support interference amount ΔF of the abdominal support rod 2 zj1 , substitute formula (1), formula (2), formula (3) and formula (4) into formula (5), as follows:

[0060] ΔF zj1 =F 4 -F 1 -(F 3 -F 2 ) (5)

[0061] According to S2-S4, when the model 4 adopts the back support formal force test, the support interference value ΔF of the back support rod 1 is obtained. zj2 , substitute formula (2), formula (3) and formula (4) into formula (6), as follows:

[0062] ΔF zj2 =F 4 -F 2 -(F 3 -F 2 ) (6).

[0063] It should be noted that in the above embodiments, as long as the technical solutions are not contradictory, they can be arranged and combined, and those skilled in the art can exhaust all possibilities based on the mathematical knowledge of arrangement and combination. Therefore, the present invention will no longer describe the technical solutions after arrangement and combination one by one, but it should be understood that the technical solutions after arrangement and combination have been disclosed by the present invention.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A low-speed wind tunnel support interference test method based on a mechanical arm support method, characterized in that: include: S1, the model (4) is subjected to aerodynamic measurement by using a normal back support rod (1) without an abdominal support rod (2) and an auxiliary support (3), that is, the model (4) is fixedly mounted on the mechanical arm (5) through the back support rod (1), and the first component of the aerodynamic force F1 measured by the balance in the test is obtained; S2, the model (4) is measured for aerodynamic force by using a normal belly support rod (2) without a back support rod (1) but with an auxiliary support (3), that is, the model (4) is fixedly mounted on the mechanical arm (5) through the belly support rod (2), and the auxiliary support (3) is mounted on the belly support rod (2), and the second component of aerodynamic force F2 measured by the balance in the test is obtained; S3, the model (4) is subjected to aerodynamic measurement by adopting a method of installing the belly support rod (2) without the back support rod (1) and the auxiliary support (3), that is, the model (4) is fixedly mounted on the mechanical arm (5) through the belly support rod (2), and the third component of the aerodynamic force F3 measured by the balance in the test is obtained; S4, the model (4) is subjected to aerodynamic measurement by using a positive abdominal support rod (2) with a back support rod (1) and an auxiliary support (3), and the fourth component of aerodynamic force F4 measured by the balance in the test is obtained; S5, according to S1-S4, it is obtained that when the model (4) adopts the abdominal support formal force measurement test, the support interference amount ΔF of the abdominal support rod (2) is zj1 ,as follows: ΔF zj1 =F4-F1-(F3-F2) (5) According to S2-S4, when the model (4) adopts the back support formal force test, the support interference value ΔF of the back support rod (1) is obtained. zj2 ,as follows: ΔF zj2 =F4-F2-(F3-F2) (6)。 2. A low-speed wind tunnel support interference test method based on a mechanical arm support method according to claim 1, characterized in that: The two ends of the back support rod (1) are respectively an ID segment and an ICD segment, the model (4) is connected to the front end of the balance, and the ID segment is fixedly connected to the rear end of the balance.

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

4. A low-speed wind tunnel support interference test method based on a mechanical arm support method according to claim 3, characterized in that: In the S1, the ICD section of the back support rod (1) is fixedly connected to the ISD section of the mechanical arm (5). The first component F1 of the aerodynamic 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 F is the interference of the back support rod (1) on the aerodynamic force of the model (4); ICD F is the interference of the ICD section of the back support rod (1) on the aerodynamic force of the model (4); ISD is the interference amount of the ISD segment of the robot (5) on the aerodynamic force of the model (4).

5. A low-speed wind tunnel support interference test method based on a mechanical arm support method according to claim 4, characterized in that: In the S2, the ICV section of the belly support rod (2) is fixedly connected to the ISV section of the mechanical arm (5), and an auxiliary bracket (3) is installed on the ICV section of the belly support rod (2). The second component F2 of the aerodynamic 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 interference amount of the IV section of the abdominal support rod (2) on the aerodynamic force of the model (4); ICV F is the interference of the ICV section of the abdominal support rod (2) on the aerodynamics of the model (4); ISV is the amount of interference caused by the ISV segment of the robot (5) on the aerodynamic force of the model (4).

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

7. A low-speed wind tunnel support interference test method based on a mechanical arm support method according to claim 6, characterized in that: In the S4, the ICV section of the abdominal support rod (2) is fixedly connected to the ISV section of the mechanical arm (5), and the two ends of the auxiliary bracket (3) are respectively fixedly connected to the ICV section of the abdominal support rod (2) and the ICD section of the back support rod (1). The back support rod (1) wake area ICW is arranged at the rear side of the ICD section of the back support rod (1). The fourth component F4 of the aerodynamic 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 interference amount of the ICW in the wake area of ​​the back support rod (1) on the aerodynamic force of the model (4).

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