An attitude angle leveling device for a semi-model of an aircraft wind tunnel test and application thereof

Abstract

The application discloses a kind of aircraft wind tunnel test half model attitude angle leveling device and application, belong to experimental aerodynamics measurement field, purpose is to solve in the half model attitude angle adjustment process on the upper wall plate of wind tunnel test section, prior art usually uses laser or gyroscope to measure, measurement process is tedious, calibration period is long, checking and adjusting time-consuming and labor-consuming problem.This leveling device includes positioning base plate, distance measuring device, for installing on the upper wall plate of test section of wind tunnel half model, the positioning base plate includes first connecting plate, second connecting plate, the first connecting plate is used to be connected with the upper wall plate of test section, the second connecting plate is arranged along vertical direction, the first connecting plate is vertically connected with second connecting plate.This application can be applicable to aircraft wind tunnel test in the half model attitude angle measurement and fast leveling installed on the upper wall plate of wind tunnel test section, simple operation, fast, high efficiency, with very high industrial application value.

Description

Technical Field

[0001] This invention relates to the field of experimental aerodynamics measurement, specifically to a device and application for leveling the attitude angle of a half-model in a wind tunnel test. More specifically, this application provides a device and application for leveling the attitude angle of a half-model installed on the upper wall of a wind tunnel, which can quickly measure the angle of attack of the half-model, simplify the leveling operation of the half-model installed on the upper wall of the wind tunnel test section, and significantly shorten the adjustment time. Background Technology

[0002] Compared to full-model wind tunnel testing, half-model wind tunnel testing offers advantages such as larger model size, higher fidelity in shape simulation, higher Reynolds number, and less support interference. The design and cabling of related balances, sensors, and other devices are also more convenient. Currently, in newly built wind tunnel facilities, to facilitate installation and reduce the impact of model and balance head weight on test results, half-models are often installed on the upper or lower wall panels of the test section. Therefore, conventional attitude angle leveling methods (such as inclinometers and bubble jets) for models installed on side panels are unsuitable and can only measure horizontal states within a plane, severely limiting the attitude angle measurement range. On the other hand, while highly accurate optical measurement methods can flexibly select model feature points, they are costly and complex to operate, making them unsuitable for scenarios requiring rapid acquisition of high-precision attitude angles during ground preparation. In summary, attitude angle measurement using half-models installed on the upper or lower wall panels introduces new challenges and difficulties to test preparation and data processing.

[0003] The measurement and calibration of the attitude angles of a semi-model directly affects the conversion of balance measurements to the body axis, which is crucial for the accurate prediction of the aircraft's lift, drag, and handling characteristics. According to a technical progress report released by an aerospace research and development consulting group, to ensure the development requirement of a drag coefficient prediction accuracy of 0.0001, the leveling and measurement error of the model's attitude angles must be less than 0.02°. For full-model tests with tail or belly support, and semi-model tests with side wall support, mechanical or optical inclinometers can be used with an accuracy of 0.01°, meeting the testing requirements. However, for semi-model tests with upper and lower wall panels, since all types of inclinometers are based on the accelerometer principle and have no gravitational component in the model's attitude direction, it is impossible to measure the attitude angles of this type of test model. Using lasers or gyroscopes, on the one hand, cannot guarantee the accuracy of attitude angle measurement; on the other hand, the instrument setup and calibration cycle at the test site is long, and inspection and adjustment are time-consuming and labor-intensive, resulting in low engineering applicability.

[0004] Therefore, there is an urgent need for a new method and / or apparatus to solve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a device and application for leveling the attitude angle of a half-model in a wind tunnel test, to solve the problems of existing technologies that typically use lasers or gyroscopes for measurement during the adjustment of the attitude angle of a half-model on the upper wall of a wind tunnel test section. These methods are cumbersome, have long calibration cycles, and are time-consuming and labor-intensive for inspection and adjustment. This invention effectively solves the problem that existing inclinometers, based on the principle of accelerometers, cannot measure the attitude angle of this type of test model when the half-model is installed on the upper wall of the wind tunnel test section. Since these inclinometers are based on the principle of accelerometers and have no gravitational component in the direction of the model's attitude movement, they cannot measure the attitude angle of this type of test model.

[0006] To achieve the above objectives, this application adopts the following technical solution.

[0007] A semi-model attitude angle leveling device for wind tunnel testing of an aircraft includes a positioning base plate, a distance measuring device, and a semi-model for mounting on the upper wall of the test section of the wind tunnel. The positioning base plate includes a first connecting plate and a second connecting plate. The first connecting plate is used to connect to the upper wall of the test section, and the second connecting plate is arranged in a vertical direction. The first connecting plate and the second connecting plate are perpendicularly connected.

[0008] The semi-model is provided with a leveling plane, the length of which is L;

[0009] The distance measuring device is mounted on the second connecting plate and can measure the distance from a set position on the second connecting plate perpendicular to the incoming flow direction to the semi-model leveling plane.

[0010] The first connecting plate and the second connecting plate are perpendicular to each other.

[0011] Preferably, the first connecting plate and the second connecting plate are integrally formed.

[0012] The second connecting plate has several process holes. These process holes on the second connecting plate help reduce the weight of the positioning substrate and facilitate measurement; however, if the actual device is lightweight and measurement is simple, process holes may not be necessary.

[0013] The second connecting plate is equipped with a scale. The scale on the second connecting plate facilitates the measurement of the distance between selected points.

[0014] Preferably, it also includes reinforcing ribs, which are connected to the first connecting plate and the second connecting plate respectively.

[0015] The first connecting plate is provided with a first threaded hole for connecting to the upper wall plate of the test section;

[0016] It also includes screws or bolts that mate with the first threaded hole, and the first connecting plate is connected to the upper wall plate of the test section through the engagement of the screws or bolts with the first threaded hole.

[0017] The distance measuring device is one or more of a vernier caliper, a depth gauge, and a laser rangefinder.

[0018] The distance measuring device has a measurement accuracy of 0.001mm-0.01mm.

[0019] The range of the distance measuring device is greater than the maximum value of all measured distances within the entire adjustment angle range.

[0020] The application of the aforementioned aircraft wind tunnel test half-model attitude angle leveling device, which is used in the attitude angle leveling of the half-model on the upper wall of the wind tunnel test section, includes the following steps:

[0021] S1. Attach the first connecting plate to the upper wall of the wind tunnel test section and make the second connecting plate parallel to the side wall of the test section;

[0022] S2. Move the positioning base plate to the set position and fix the first connecting plate to the upper wall of the test section.

[0023] S3. Determine whether the second connecting plate is parallel to the side wall of the test section; if not, return to step S1 to readjust; if parallel, proceed to step S4.

[0024] S4. Based on the length L of the leveling plane on the half-model and the range of the angle of attack to be leveled [ β 1, β 2] Determine the measurement point on the second connecting plate. x 1. x The difference Δ between 2 x Δ x = x 1- x 2, and Δ x <min{ L cos β 1, L cos β 2};

[0025] S5. Based on the positional change of the leveling plane on the semi-model and the Δ determined in step S4... x Select the corresponding two measurement points on the second connecting plate. x 1. x 2;

[0026] S6. Select n angles from the range of angles of attack to be leveled, in ascending order as follows: α 1. α 2、…、 α i … α n n is a natural number and n≥3, n≥i≥1;

[0027] S7, Regarding setting the angle of attack α i Measure and record the measuring points x 1. x 2. Corresponding distance to the leveling plane of the model body y 1i , y 2i And calculate the difference Δ y i = y 1i - y 2i ;

[0028] S8, Calculate and set angle of attack α i Corresponding actual angle of attack The calculation formula is as follows:

[0029] ;

[0030] S9. Calculate the actual angle of attack in step S8. With encoder angle of attack value Compare and calculate the difference Δ α i Δ α i =│ - │; if Δ α i Less than the encoder error threshold α R If Δ α i Greater than the encoder error threshold α R Then the encoder needs to be adjusted so that the encoder angle of attack value matches the actual angle of attack calculated in step S8, and then the new Δ needs to be compared again. α i With set value α R ;

[0031] S10. After step S9 is completed, adjust the actual angle of attack of the half-model to 0° to complete the half-model attitude angle leveling.

[0032] in, To set the angle of attack α i The corresponding encoder angle of attack value, α R This is the encoder error threshold.

[0033] LTo adjust the length of the plane on the semi-model, β 1 represents the lower limit of the angle range to be leveled. β 2 represents the upper limit of the angle range to be leveled. x 1 is the first measuring point on the second connecting plate. x 2 is the second measuring point on the second connecting plate, Δ x The first measuring point on the second connecting plate x 1. The second measuring point on the second connecting plate x The difference between 2; n is a natural number and n≥3, n≥i≥1, α i Set the angle of attack for the i-th element; y 1i The first measuring point on the second connecting plate x 1. Distance from the leveling plane of the model body. y 2i The second measuring point on the second connecting plate x 2. The distance from the model's leveling plane, Δ y i for y 1i and y 2i The difference, To set the angle of attack α i The corresponding actual angle of attack.

[0034] In step S2, the first connecting plate is connected to the upper wall plate of the test section by screws or bolts.

[0035] In step S2, the set position satisfies the following conditions:

[0036] Condition 1: Within the range of variable angle of attack, the semi-model does not collide with the positioning base plate;

[0037] Condition 2: The second connecting plate is parallel to the side wall of the test section;

[0038] Condition 3: The distance between the second connecting plate and the leveling plane of the half-model along the direction perpendicular to the incoming flow is within the range of the measuring device.

[0039] In this application, the test section sidewall is parallel to the incoming flow direction. When the second connecting plate is parallel to the test section sidewall, the second connecting plate is parallel to the incoming flow direction.

[0040] When adjusting the attitude angle of a half-model installed on the upper wall of a wind tunnel test section, this application has the following advantages compared with existing methods such as direct leveling based on a level and optical leveling based on laser collimation:

[0041] (1) When using the leveling device of the present invention to measure the attitude angle of the upper wall panel half model of the wind tunnel test section, the attitude angle range that can be measured is wide and can be associated with the airflow direction of the wind tunnel. The leveling result will not deviate from the airflow reference.

[0042] (2) The leveling device of the present invention has a simple structure, low cost, and is easy to operate. It is not easily affected by external interference. While having few measurement parameters, the measurement results are accurate enough to meet the high efficiency and high precision requirements of angle of attack leveling in the test site. It has extremely high engineering application value and good application prospects. It can effectively solve the problem of measuring the attitude angle of the upper wall plate half model in the wind tunnel test section.

[0043] (3) The leveling device and leveling method proposed in this invention can be applied to other large wind tunnels and have the advantage of good engineering applicability.

[0044] In summary, this application is applicable to the measurement and rapid leveling of the attitude angles of a half-model installed on the upper wall of the wind tunnel test section during wind tunnel testing of aircraft. It is simple to operate, fast, and efficient, possessing extremely high industrial application value. As a general-purpose device, this application is ingeniously conceived and rationally designed, capable of meeting the need for rapid and accurate measurement of the attitude angles of a half-model at the test site, and has extremely high application value. Attached Figure Description

[0045] The present invention will be described by way of example and with reference to the accompanying drawings, wherein:

[0046] Figure 1 This is a schematic diagram of the positioning substrate in Example 1 (threaded holes are omitted for simplicity).

[0047] Figure 2 This is a schematic diagram of the measurement process.

[0048] Figure 3 This is a flowchart illustrating the installation and leveling process of the attitude angle leveling device for the half-model aircraft used in the wind tunnel test in this application.

[0049] The markings in the diagram are: 1. First connecting plate, 2. Second connecting plate, 3. Reinforcing rib, 4. Process hole, 5. Positioning substrate, 6. Half model, 7. Leveling plane. Detailed Implementation

[0050] All features disclosed in this specification, or steps in all methods or processes disclosed herein, may be combined in any way, except for mutually exclusive features and / or steps.

[0051] Any feature disclosed in this specification, unless otherwise stated, may be replaced by other equivalent or similar features. That is, unless otherwise stated, each feature is merely one example of a series of equivalent or similar features.

[0052] Example 1

[0053] It should be noted that the leveling device in this embodiment is installed in a wind tunnel to level the attitude angle of a large aircraft half-model.

[0054] This embodiment provides a semi-model attitude angle leveling device for wind tunnel testing of an aircraft, comprising a positioning base plate, a distance measuring device, and a semi-model for mounting on the upper wall panel of the test section in the wind tunnel. The positioning base plate includes a first connecting plate and a second connecting plate. The first connecting plate is connected to the upper wall panel of the test section, and the second connecting plate is arranged vertically, perpendicularly connected to the first connecting plate. A leveling plane is provided on the semi-model; in this embodiment, the length of the leveling plane is L = 600.00 mm. The first and second connecting plates are perpendicular to each other. Furthermore, the first and second connecting plates are integrally formed. Figure 1 A schematic diagram of the positioning substrate is provided (threaded holes are omitted for simplicity). Figure 1 As shown, the second connecting plate has four through holes to reduce weight and facilitate measurement.

[0055] The distance measuring device cooperates with the second connecting plate and can measure the distance between a set position on the second connecting plate and the leveling plane of the half-model. In this embodiment, the distance measuring device is a commercially available product, and can be a vernier caliper, depth gauge, laser rangefinder, or other existing device, depending on the required measurement accuracy. In this embodiment, the second connecting plate is provided with a scale of 70mm to 1400mm (meaning the overall length of the scale is 70mm to 1400mm) to facilitate the measurement of the distance between selected points, with a measurement accuracy of 0.1mm; furthermore, it also includes 5 reinforcing ribs, located at the 3 gaps of the through hole, with both ends connected to the first and second connecting plates as a whole. At the same time, the first connecting plate is provided with 12 threaded holes for connecting to the upper wall plate of the test section, and also includes screws or bolts that cooperate with it. In a specific example, a depth gauge is used as the distance measuring device, with a measurement range of 0 to 700mm and a measurement accuracy of 0.01mm.

[0056] Furthermore, this embodiment provides an application of the aforementioned device, using it for attitude angle leveling of a large aircraft semi-model, including the following steps. Figure 2 A schematic diagram of the measurement process is provided. Figure 3 A flowchart is provided for the installation and leveling of the attitude angle leveling device for a half-model aircraft tested in a wind tunnel.

[0057] S1. Attach the first connecting plate to the upper wall of the wind tunnel test section and make the second connecting plate parallel to the side wall of the test section.

[0058] S2. Move the positioning base plate to the set position and fix the first connecting plate to the upper wall of the test section. In a specific example, the first connecting plate is fixed to the upper wall of the wind tunnel test section by screws or bolts engaging with the threaded holes on the first connecting plate.

[0059] S3. After several adjustments, confirm that the second connecting plate is parallel to the side wall of the test section, and proceed to step S4.

[0060] S4. The length of the leveling plane on the half-model is L = 600.00 mm. The range of the angle of attack to be leveled is [-5°, 20°]. The calculated min{600cos(-5°), 600cos(20°)} = 563.81 mm. For ease of calculation, the measuring point on the second connecting plate is set. x 1. x The difference between 2 and Δx is 500.0 mm.

[0061] S5. Based on the position change of the leveling plane on the semi-model in this embodiment and the Δ determined in S4... x =500.0mm, the position of the measuring point is determined on the second connecting plate. x 1 = 1100.0 mm x 2 = 600.0 mm.

[0062] S6. The range of angles of attack to be leveled is [-5°, 20°]. Select 6 angles from this range, arranged in ascending order as follows: α 1 = -5° α 2=0°、 α 3=5° α 4 = 15° α 5 = 15° α 6 = 20°.

[0063] S7, Regarding setting the angle of attack α i Measure and record the measurement points x 1. x 2. Corresponding distance to the leveling plane of the model body y 1i , y 2i And calculate the difference Δ y i = y 1i - y 2i See attached diagram for a schematic diagram of the measurement process. Figure 2 The measurement results are shown in Table 1.

[0064] S8. The set angle of attack is obtained using the following formula. α i Corresponding actual angle of attack The calculation formula is as follows:

[0065] .

[0066] The measurement results are shown in Table 1.

[0067] S9. Calculate the actual angle of attack in step S8. Encoder angle of attack Compare and calculate the difference Δ α i =│ - The measurement results are shown in Table 1.

[0068] All differences Δ α i =│ - All are less than the encoder error threshold. α R =0.02°, so the encoder angle of attack value can be considered equal to the actual angle of attack.

[0069] S10. Make the actual angle of attack equal to 0° to complete the attitude angle leveling of the half-model.

[0070] Furthermore, in step S2, the set position satisfies the following conditions:

[0071] Condition 1: Within the range of variable angle of attack, the semi-model does not collide with the positioning base plate;

[0072] Condition 2: The second connecting plate is parallel to the side wall of the test section;

[0073] Condition 3: The distance between the second connecting plate and the leveling plane of the semi-mold model is within the measurement range of the measuring device.

[0074] Table 1 shows the attitude angle measurement results of a large aircraft half-model installed on the upper wall of a wind tunnel. The test results show that the present invention can realize the attitude angle leveling and measurement of the half-model on the upper wall of the wind tunnel test section. It is fast, accurate, and easy to operate, and has extremely high application value.

[0075] Table 1. Attitude angle measurement results of a large aircraft semi-model mounted on the upper wall of a wind tunnel.

[0076]

[0077] This invention is not limited to the specific embodiments described above. The invention extends to any new feature or combination disclosed in this specification, as well as any new method or process step or combination disclosed herein.

Claims

1. A wind tunnel test half-model attitude angle leveling device for an aircraft, characterized in that, The system includes a positioning base plate, a distance measuring device, and a semi-model for mounting on the upper wall of the test section of a wind tunnel. The positioning base plate includes a first connecting plate and a second connecting plate. The first connecting plate is used to connect to the upper wall of the test section, and the second connecting plate is arranged in a vertical direction. The first connecting plate and the second connecting plate are perpendicularly connected. The semi-model is provided with a leveling plane, the length of which is... L ; The distance measuring device is mounted on the second connecting plate and can measure the distance from a set position on the second connecting plate perpendicular to the incoming flow direction to the semi-model leveling plane.

2. The attitude angle leveling device for a semi-model of an aircraft wind tunnel test according to claim 1, characterized in that, The first connecting plate and the second connecting plate are perpendicular to each other.

3. The attitude angle leveling device for a semi-model of an aircraft wind tunnel test according to claim 1, characterized in that, The second connecting plate is provided with a scale.

4. The attitude angle leveling device for a semi-model of an aircraft wind tunnel test according to claim 1, characterized in that, The first connecting plate is provided with a first threaded hole for connecting to the upper wall plate of the test section; It also includes screws or bolts that mate with the first threaded hole, and the first connecting plate is connected to the upper wall plate of the test section through the engagement of the screws or bolts with the first threaded hole.

5. The attitude angle leveling device for a semi-model of an aircraft wind tunnel test according to claim 1, characterized in that, The distance measuring device has a measurement accuracy of 0.001mm-0.01mm.

6. The attitude angle leveling device for a semi-model of an aircraft wind tunnel test according to claim 1, characterized in that, The range of the distance measuring device is greater than the maximum value of all measured distances within the entire adjustment angle range.

7. The application of the attitude angle leveling device for a semi-model of an aircraft wind tunnel test as described in any one of claims 1 to 6, characterized in that, The device is used for leveling the attitude angle of a half-model on the upper wall of a wind tunnel test section, and includes the following steps: S1. Attach the first connecting plate to the upper wall of the wind tunnel test section and make the second connecting plate parallel to the side wall of the test section; S2. Move the positioning base plate to the set position and fix the first connecting plate to the upper wall of the test section. S3. Determine whether the second connecting plate is parallel to the side wall of the test section; if not, return to step S1 to readjust; if parallel, proceed to step S4. S4. Based on the length of the leveling plane on the half-model L The range of angle of attack to be leveled [ β 1, β 2] Determine the measurement point on the second connecting plate. x 1. x The difference Δ between 2 x Δ x = x 1- x 2, and Δ x <min{ L cos β 1, L cos β 2}; S5. Based on the positional change of the leveling plane on the semi-model and the Δ determined in step S4... x Select the corresponding two measurement points on the second connecting plate. x 1. x 2; S6. Select n angles from the range of angles of attack to be leveled, in ascending order as follows: α 1. α 2、…、 α i … α n n is a natural number and n≥3, n≥i≥1; S7, Regarding setting the angle of attack α i Measure and record the measuring points x 1. x 2. Corresponding distance to the leveling plane of the model body y 1i , y 2i And calculate the difference Δ y i = y 1i - y 2i ; S8, Calculate and set angle of attack α i Corresponding actual angle of attack The calculation formula is as follows: ； S9. Calculate the actual angle of attack in step S8. With encoder angle of attack value Compare and calculate the difference Δ α i Δ α i =│ - │; if Δ α i Less than the encoder error threshold α R If so, the encoder angle of attack value is considered to be equal to the actual angle of attack; If Δ α i Greater than the encoder error threshold α R Then the encoder needs to be adjusted so that the encoder angle of attack value matches the actual angle of attack calculated in step S8, and then the new Δ needs to be compared again. α i With set value α R ; S10. After step S9 is completed, adjust the actual angle of attack of the half-model to 0° to complete the half-model attitude angle leveling.

8. The application according to claim 7, characterized in that, in, To set the angle of attack α i The corresponding encoder angle of attack value, α R This is the encoder error threshold.

9. The application according to claim 7 or 8, characterized in that, In step S2, the set position satisfies the following conditions: Condition 1: Within the variable angle of attack range, the semi-model does not collide with the positioning base plate; Condition 2: The second connecting plate is parallel to the side wall of the test section; Condition 3: The distance between the second connecting plate and the leveling plane of the half-model along the direction perpendicular to the incoming flow is within the range of the measuring device.

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