Device for adjusting roll angle attitude of model in wind tunnel

Abstract

The utility model discloses a device for adjusting the roll angle attitude of a model in a wind tunnel. The device comprises a reference platform, a positioning pin and an electronic angle gauge. A through hole is machined in the reference platform, the reference platform is connected with a model rear section hole shaft in a matched mode, a disc is machined on the side, close to the model end face, outside the reference platform, a cuboid is machined on the side away from the model end face, and four faces, parallel to the model rear section axis, of the cuboid serve as reference faces; the positioning pin is used for sequentially entering the pin holes of the reference platform and the rear section of the model for positioning and fastening the rear section of the model and the reference platform into a whole; and selecting a proper reference surface on the reference platform, placing the electronic angle gauge to measure the inclination angle of the reference surface, and rotating the model to enable the electronic angle gauge to display a required angle, thereby completing the adjustment of the roll angle attitude of the model. According to the utility model, the problem of inaccurate installation of the roll angle of the model in the wind tunnel is solved, and the device plays an important role in realizing accurate installation of the roll angle of the model and improving the test precision.

Description

Technical Field

[0001] The utility model relates to a device for adjusting the roll angle attitude of a model in a wind tunnel, belonging to the technical field of test tooling. Background Technique

[0002] Wind tunnel tests are based on the principle of relativity of motion. The model of the aircraft is fixed on the wind tunnel mechanism, and artificial air flow is created to simulate various complex flight states in the air and obtain test data. The attitude changes of the model include three degrees of freedom: angle of attack, sideslip angle, and roll angle. The currently used wind tunnel mechanism can change the angle of attack and sideslip angle of the model attitude, but cannot achieve the transformation of the roll angle of the model body. Because the control of the roll angle is considered to place a motor at the tail of the strut for rotation control, and currently, considering factors such as the requirements of mechanical precision, the influence of vacuum degree and temperature environment on the motor operation during the test, and the possible electromagnetic interference of the motor on the balance, it has not been applied in practice. In the actual test preparation stage, after manually adjusting the roll angle attitude of the model, a series of tests are carried out at this roll angle. To change the traditional method of the model roll angle, the roll angle attitude of the model test needs to be considered in the design and processing stage. At this roll angle, lines are engraved on both sides of the cylindrical section of the rear part of the model. During installation, by adjusting the height of the lines on both sides, when they are consistent, it is considered that the roll angle of the model installation meets the requirements. However, this method has some problems: Measuring the height of the engraved lines in the method requires the line of sight of the observer to be horizontal with the engraved lines of the model, which inevitably brings human error. There are also the influence of the width of the engraved lines on the observation accuracy, whether there is a suitable surface for engraving lines on the model, the influence of the engraved lines on the outer surface of the model on the test results, the requirements for the reference platform for measuring the height of the engraved lines, and the requirement that the engraved lines need to be determined in the design and processing stage. All these make the accuracy and popularity of this method limited. Content of the Utility Model

[0003] The technical problem solved by the utility model is: overcoming the deficiencies of the prior art, providing a device for adjusting the roll angle attitude of a model in a wind tunnel, and solving the problem of inaccurate installation of the roll angle of the model in the wind tunnel.

[0004] The technical solution adopted by the utility model is: a device for adjusting the roll angle attitude of a model in a wind tunnel, which includes a reference platform, a positioning pin, and an electronic angle gauge;

[0005] Through holes are machined inside the reference platform. The wind tunnel model adopts a tail support method. The inside of the rear part of the model is connected to the wind tunnel mechanism through a balance and a strut. The outside of the rear part of the model is a cylindrical shaft, and the reference platform is connected with the hole and shaft of the rear part of the model in a matching manner. A disc is machined on one side of the outside of the reference platform close to the end face of the model, and a cuboid is machined on the other side far from the end face of the model. The four faces of the cuboid parallel to the axis of the rear part of the model are used as reference faces. Pin holes for positioning with the rear part of the model are machined on the reference platform;

[0006] The positioning pin is used to sequentially enter the pin holes of the reference platform and the rear section of the model for positioning and fastening the rear section of the model and the reference platform as a whole.

[0007] Select the reference plane on the reference platform for placing the electronic angle gauge. The electronic angle gauge is used to measure the inclination angle of the reference plane. Rotate the model to make the electronic angle gauge display the required angle, thus completing the adjustment of the roll angle attitude of the model.

[0008] Preferably, the inner diameter of the through hole of the reference platform is the same as the outer diameter of the cylindrical shaft protruding from the rear section of the model, with a positive tolerance for the through hole and a negative tolerance for the cylindrical shaft.

[0009] Preferably, the geometric centers of the disc and the cuboid pass through the axis of the model. The diameter of the disc is greater than or equal to the diagonal of the surface parallel to the disc on the cuboid. The disc is perpendicular to the axis of the model, thus forming an upright surface for the electronic angle gauge to rely on.

[0010] Preferably, after the reference platform and the model are assembled, when the roll angle is 0°, one of the reference planes is in a horizontal state for placing the electronic level. That is, when the other three planes are horizontal upwards, the model is in a roll angle of 90°, 180°, and 270° in sequence.

[0011] Preferably, the area of the reference plane on the reference platform is larger than the bottom area of the electronic angle gauge, that is, the electronic angle gauge can be completely placed on the plane.

[0012] Preferably, the flatness requirement of the reference plane is less than or equal to 0.03 mm.

[0013] Preferably, a threaded hole is machined at the top of the positioning pin for easy pulling out, and it cannot protrude from the reference plane after installation.

[0014] Preferably, the electronic angle gauge has magnetic adsorption ability and can be adsorbed on the reference platform.

[0015] Preferably, the measurement accuracy requirement of the electronic angle gauge is less than 0.005°.

[0016] Preferably, the resolution of the electronic angle gauge is less than 0.001°.

[0017] The beneficial effects of the present utility model compared with the prior art are as follows:

[0018] (1) By processing the reference platform, the present utility model uses a sensitive and accurate electronic device to digitally display the installation angle, which is simple and direct, avoiding the error of manual measurement.

[0019] (2) The structure of the present utility model is simple and easy to process. There is no need to consider whether there are suitable surface markings on the outer surface of the model, and it has a wide applicability. At the same time, it also avoids the influence of the surface markings on the outer surface of the model on the test measurement data.

[0020] (3) The present utility model can arbitrarily determine the roll angle according to the needs of the test, and is not restricted by the roll angle state that must be considered in advance in the traditional method. It can be adjusted at any time according to the requirements during the test, with high flexibility and better serving customers. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic exploded view of the present utility model;

[0022] Figure 2 is a schematic external view of the reference platform of the present utility model. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The present utility model will be further explained and described below in conjunction with the accompanying drawings of the specification and the detailed embodiments.

[0024] As Figure 1 shown, a device for adjusting the roll angle attitude of a model in a wind tunnel provided by the present utility model includes a reference platform 1, a positioning pin 2, and an electronic angle meter 3. As Figure 2 shown, the reference platform 1 is drilled, including connection holes 1-1 with the rear section of the model, positioning pin holes 1-2, and weight reduction holes 1-3.

[0025] A through hole is machined inside the reference platform 1. The wind tunnel model adopts a tail support method. The inside of the rear section of the model is connected to the wind tunnel mechanism through a balance and a strut, and the outside of the rear section of the model is a cylindrical shaft. The reference platform and the rear section of the model are connected by hole-shaft fit. A disc is machined on one side of the reference platform close to the model end face, and a cuboid is machined on the side far from the model end face. Four faces of the cuboid parallel to the axis of the rear section of the model are used as reference planes. A pin hole for positioning with the rear section of the model is machined on the reference platform;

[0026] The positioning pin 2 is used to sequentially enter the pin holes of the reference platform and the rear section of the model for positioning and fastening the rear section of the model and the reference platform as a whole;

[0027] The electronic angle meter 3 is placed on a suitable reference plane of the reference platform to measure the inclination angle of the reference plane, and the model is rotated to make the electronic angle meter display the required angle, thus completing the adjustment of the roll angle attitude of the model.

[0028] In a specific embodiment of the present utility model, the wind tunnel model adopts a tail support method. The model is divided into front and rear parts. A hole is provided inside the front part at the split, and a cylindrical shaft extends from the rear part. The front and rear parts are connected by hole-shaft fit. When installing the model in the wind tunnel, the rear section 4 of the model is first sleeved from the head of the balance and the strut 5, the attitude is determined and installed, and then the front section of the model is installed.

[0029] Preferably, the inner diameter of the through hole of the reference platform is the same as the outer diameter of the cylindrical shaft extending from the rear section of the model, with a positive tolerance for the through hole and a negative tolerance for the cylindrical shaft to ensure a tight fit.

[0030] Preferably, the geometric centers of the disc and the cuboid pass through the axis of the model. The diameter of the disc is greater than or equal to the diagonal of the surface parallel to the disc on the cuboid. The disc is perpendicular to the axis of the model, thereby forming an upright surface on which the electronic angle gauge can rely.

[0031] Preferably, the reference platform is appropriately lightened at places where it does not affect the fit.

[0032] Preferably, after the model is assembled with the reference platform, when the roll angle is 0°, one of the reference surfaces is in a horizontal state for placing the electronic angle gauge. When the other three surfaces face upwards horizontally, the model is in a roll angle of 90°, 180°, and 270° in sequence.

[0033] Preferably, the areas of the four reference surfaces of the reference platform must be larger than the bottom area of the electronic angle gauge, that is, the electronic angle gauge can be completely placed on the plane. For the electronic angle gauges on the market, the required area is above 100×30 mm.

[0034] Preferably, the flatness requirement of the reference surface is less than or equal to 0.03 mm.

[0035] Preferably, a threaded hole is machined at the top of the positioning pin for easy extraction, and it cannot protrude from the reference surface after installation.

[0036] Preferably, the electronic angle gauge has magnetic adsorption ability and can be adsorbed on the reference platform. The measurement accuracy requirement of the electronic angle gauge is less than 0.005°, and the resolution is less than 0.001°.

[0037] Preferably, as Figure 2 shown, a plurality of weight-reducing holes are provided on the reference platform of the present utility model.

[0038] Because in the design and processing of the reference platform, it is required that when the roll angle of the model is 0°, one of the reference surfaces faces upwards horizontally. Therefore, when actually installing the model in the wind tunnel, the electronic angle gauge is placed on this surface, and when it shows 0°, it is the state of the roll angle of the model being 0°. If it is required that the roll angle of the model Ф≤45°, rotate the model until the electronic angle gauge on this surface shows this angle; if it is required that the model rotates 45≤Ф≤90°, the reference platform rotates accordingly, and the adjacent reference surface gradually faces upwards. The electronic angle gauge is placed on this adjacent reference surface, and it shows the reverse direction (90-Ф)°. And so on, flexibly apply the corresponding reference surface for measurement.

[0039] Although the present utility model has been disclosed above with the preferred embodiments, it is not intended to limit the present utility model. Any person skilled in the art can make possible changes and modifications to the technical solution of the present utility model without departing from the spirit and scope of the present utility model. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present utility model without departing from the content of the technical solution of the present utility model shall fall within the protection scope of the technical solution of the present utility model.

Claims

1. A device for adjusting the roll angle attitude of a model in a wind tunnel, characterized in that It includes a reference platform, a positioning pin and an electronic angle gauge; A through hole is machined inside the reference platform. The model adopts a tail support method. The inner part of the rear section of the model is connected to the wind tunnel mechanism through a balance and a strut. The outer part of the rear section of the model is a cylindrical shaft. The reference platform is connected with the hole and shaft of the rear section of the model in a mating way. A disc is machined on one side of the reference platform close to the end face of the model, and a cuboid is machined on the side far from the end face of the model. The four faces of the cuboid parallel to the axis of the rear section of the model are used as reference planes. A pin hole for positioning with the rear section of the model is machined on the reference platform; The positioning pin is used to sequentially enter the pin holes of the reference platform and the rear section of the model for positioning and fastening the rear section of the model and the reference platform as a whole; Select the reference plane on the reference platform for placing the electronic angle gauge. The electronic angle gauge is used to measure the inclination angle of the reference plane. Rotate the model to make the electronic angle gauge display the required angle, that is, the adjustment of the roll angle attitude of the model is completed.

2. The device for adjusting the roll angle attitude of a model in a wind tunnel according to claim 1, characterized in that, The inner diameter of the through hole of the reference platform is the same as the outer diameter of the cylindrical shaft protruding from the rear section of the model, with a positive tolerance for the through hole and a negative tolerance for the cylindrical shaft.

3. The device for adjusting the roll angle attitude of a model in a wind tunnel according to claim 1, characterized in that, The geometric centers of the disc and the cuboid pass through the axis of the model. The diameter of the disc is greater than or equal to the diagonal of the surface parallel to the disc on the cuboid. The disc is perpendicular to the axis of the model, so as to form an upright surface for the electronic angle gauge to rely on.

4. A device for adjusting the roll angle attitude of a model in a wind tunnel according to claim 1, characterized in that, After the reference platform and the model are assembled, when the roll angle is 0°, one of the reference planes is in a horizontal state for placing an electronic level gauge, that is, when the other three faces are horizontally upward, the model is in roll angles of 90°, 180° and 270° in sequence.

5. The device for adjusting the roll angle attitude of a model in a wind tunnel according to claim 1, characterized in that, The area of the reference plane on the reference platform is larger than the bottom area of the electronic angle gauge, that is, the electronic angle gauge can be completely placed on the plane.

6. The device for adjusting the roll angle attitude of a model in a wind tunnel according to claim 1, wherein, The flatness requirement of the reference plane is less than or equal to 0.03 mm.

7. A device for adjusting the roll angle attitude of a model in a wind tunnel according to claim 1, characterized in that, A threaded hole is machined at the top of the positioning pin for easy pulling out, and it cannot protrude from the reference plane after installation.

8. A device for adjusting the roll angle attitude of a model in a wind tunnel according to claim 1, characterized in that, The electronic angle gauge has magnetic adsorption ability and can be adsorbed on the reference platform.

9. The device for adjusting the roll angle attitude of a model in a wind tunnel according to claim 1, characterized in that, The measurement accuracy requirement of the electronic angle gauge is less than 0.005°.

10. A device for adjusting the roll angle attitude of a model in a wind tunnel according to claim 1, characterized in that, The resolution of the electronic angle gauge is less than 0.001°.

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