A wind tunnel test propeller blade angle adjusting device and adjusting method

Abstract

A kind of wind tunnel test propeller blade angle adjusting device and adjusting method, contain blade angle adjusting pedestal, blade angle adjusting datum, blade angle measurement datum, blade angle adjusting pedestal contain adjustment platform, adjustment platform is equipped with hub simulation block and blade angle measurement datum mounting seat, The blade angle adjusting datum can be placed between the hub simulation block of adjustment platform and blade angle measurement datum mounting seat, there is first datum face in the lower end of blade angle adjusting datum, the curvature of first datum face is consistent with the curvature of hub simulation surface on hub simulation block, the upper end of blade angle adjusting datum is equipped with second datum face, the included angle between second datum face and blade angle adjusting datum body can be adjusted, second datum face and blade angle measurement position surface match;The blade angle measurement datum body contain measurement datum face and measurement surface, there is pre-biased included angle between measurement datum face and measurement surface, blade angle measurement datum body is hinged on blade angle measurement datum mounting seat, measurement datum face and the second datum face of blade angle adjusting datum match.

Description

Technical Field

[0001] This invention belongs to the field of aerodynamic wind tunnel testing, and relates to a propeller blade angle adjustment device and adjustment method for propeller aircraft dynamic simulation wind tunnel testing. Background Technology

[0002] Propeller propulsion systems are traditional aircraft propulsion systems. On aircraft equipped with piston engines or turboprop engines, the propeller converts the engine's power into thrust. Propeller propulsion systems have a significant impact on aircraft aerodynamic characteristics, making them a crucial factor affecting aircraft performance and safety. The effects of propeller propulsion include both direct effects (i.e., the effects of propeller thrust and torque) and indirect effects (i.e., slipstream effects). Propeller propulsion significantly increases the aircraft's lift coefficient, effectively improving takeoff and landing performance; simultaneously, it increases the drag coefficient, affecting the aircraft's range; more importantly, propulsion typically reduces pitch and directional stability, impacting handling characteristics. Due to the complexity of propeller operating conditions and slipstreams, current research on the effects of propeller propulsion widely employs wind tunnel testing methods to provide propulsion data for aircraft design.

[0003] Wind tunnel tests simulating propeller aircraft power generally employ a method that simulates the Tc (thrust)-J (propellant ratio) of a real aircraft. The general procedure for wind tunnel testing is as follows: First, based on a series of typical flight conditions of a real aircraft, a Tc-J curve is fitted. This curve is then used as the target curve for the wind tunnel simulation. In individual propeller tests, the blade angle of the test propeller is adjusted to simulate the given Tc-J curve, obtaining a series of blade angle, test wind speed, and propeller speed data corresponding to the thrust coefficient Tc. After obtaining the correspondence between the thrust coefficient Tc and the blade angle, test wind speed, and propeller speed, a full-aircraft power simulation wind tunnel test can be conducted. One wind tunnel start corresponds to one thrust coefficient. If the thrust coefficient needs to be changed, the blade angle must be adjusted according to the relationship between the thrust coefficient and blade angle calibrated in the individual propeller wind tunnel tests.

[0004] Because propeller-driven aircraft power simulation wind tunnel tests are typically conducted in wind tunnels of 8 meters or 4 meters in size, the scaled-down model has limited space for the propeller hub and blade cap, making it impossible to design and manufacture an automatic blade angle adjustment mechanism. Manual adjustment is therefore required. In previous propeller power simulation wind tunnel tests, adjusting the propeller blade angle typically required shutting down the wind tunnel, removing the propeller hub (including blades) and blade cap from the wind tunnel test model, moving the hub and blades out of the wind tunnel to the wind tunnel control room, using specialized blade angle adjustment and measurement devices to adjust the blades to the required angle, and then transferring the adjusted hub and blades back into the wind tunnel for reassembly onto the wind tunnel test model for subsequent wind tunnel tests. As can be seen from this process, changing the propeller blade angle requires disassembling and reassembling the entire propeller system, consuming significant time and manpower, and impacting the overall test schedule. Furthermore, when conducting multiple tests under different test conditions at the same tension coefficient, it is not convenient to measure the blade angle on the wind tunnel test model between each test run to check whether the blade angle has changed due to the load. In other words, it is not convenient to check and adjust the propeller blade angle at any time. Summary of the Invention

[0005] To address the problems of existing blade angle adjustment devices, this invention proposes a novel blade angle adjustment device and method for wind tunnel testing of propeller-driven aircraft. This device allows setting the angle of a plane relative to the horizontal plane in the wind tunnel operating room, then placing the plane angle device on the wind tunnel test model. The propeller blade angle is directly calibrated and set at the propeller position on the wind tunnel test model, avoiding the need to disassemble and reinstall the propeller system from the test model. Furthermore, it enables the measurement and adjustment of the propeller blade angle during any interval of wind tunnel testing, improving test efficiency and the accuracy of dynamic parameter simulation.

[0006] A wind tunnel test propeller blade angle adjustment device, wherein the blades are connected to a hub, is characterized in that the blade angle adjustment device includes a blade angle adjustment base, a blade angle adjustment reference, and a blade angle measurement reference. The blade angle adjustment base includes an adjustment platform, on which a hub simulation block and a blade angle measurement reference mounting base are provided. The hub simulation block has a hub simulation surface perpendicular to the adjustment platform. The blade angle adjustment reference can be placed between the hub simulation block and the blade angle measurement reference mounting base on the adjustment platform. The body of the blade angle adjustment reference is a plate-like structure, with a [missing information - likely a design element] at its lower end. The first reference surface is an arc-shaped surface whose curvature matches that of the rotor hub simulation surface on the rotor hub simulation block. A second reference surface is provided at the upper end of the rotor blade angle adjustment reference. This second reference surface is a lateral plane, and the angle between it and the rotor blade angle adjustment reference body is adjustable. The second reference surface matches the surface of the rotor blade angle measurement position. The rotor blade angle measurement reference body contains a measurement reference surface and a measurement surface, with a pre-biased angle between them. The rotor blade angle measurement reference body is hinged to the rotor blade angle measurement reference mounting base, and the measurement reference surface matches the second reference surface of the rotor blade angle adjustment reference.

[0007] The vertical distance between the center of the first reference plane and the second reference plane is 0.7 times the blade rotation radius.

[0008] The upper end of the blade angle adjustment reference body is connected to a blade angle setting block via a connecting block. The blade angle setting block is a semi-circular flat plate structure. One side of the blade angle setting block is a second reference surface. The blade angle setting block is provided with an arc groove. A pin connects the blade angle setting block to the connecting block through the arc groove. The connecting block is fixed to the upper end of the blade angle adjustment reference body, so that the blade angle setting block can rotate in a plane relative to the pin along the arc groove to adjust the angle between the second reference surface and the blade angle adjustment reference body.

[0009] A clamping element is provided between the surface of the blade angle setting block and the pin shaft. The clamping element can fix and press the blade angle setting block. An angle indicator scale line is also provided on the surface of the blade angle setting block. The angle indicator scale line is consistent with the angle between the second reference surface and the blade angle adjustment reference body.

[0010] The blade angle measurement reference includes a first measuring block and a second measuring block, which are parallel and coaxially connected. The first measuring block has a measuring reference surface and a first measuring surface, and there is a pre-offset angle between the measuring reference surface and the first measuring surface. The second measuring block has a second measuring surface, which is parallel to the measuring reference surface. The connecting shaft between the first measuring block and the second measuring block is hinged to the blade angle measurement reference mounting base.

[0011] A parallel and coaxially connected adjustment plate is provided between the first and second measuring blocks. The adjustment plate has an arc-shaped slide. The adjustment plate is also connected to the blade angle measuring reference mounting base through the arc-shaped slide and the clamping screw. The adjustment plate can drive the first and second measuring blocks to rotate. The arc-shaped slide and the clamping screw of the adjustment plate can limit the rotation of the first and second measuring blocks.

[0012] This application also provides a method for adjusting the blade angle of a wind tunnel test propeller, characterized by the following: 1) using the aforementioned wind tunnel test propeller blade angle adjustment device; 2) adjusting the first or second measuring surface of the blade angle measurement reference relative to the adjustment platform to match the preset blade angle and then fixing it; 3) placing the blade angle adjustment reference on the adjustment platform of the blade angle adjustment base, so that the first reference surface is attached to the hub simulation surface of the hub simulation block, and the second reference surface at its upper end is attached to the measuring reference surface of the blade angle measurement reference, keeping the second reference surface relative to the blade angle adjustment reference body unchanged; 4) then placing the blade angle adjustment reference on the propeller hub, so that the first reference surface at the lower end of the blade angle adjustment reference is attached to the hub surface, adjusting the propeller blade angle so that the blade surface is attached to the second reference surface at the upper end of the blade angle adjustment reference, thereby fixing the relative position of the blade and the hub; 5) using the same method to complete the adjustment of the blade angle of all blades.

[0013] The beneficial effects of this application are as follows: 1) The blade angle adjustment device can adjust and maintain the second reference surface of the blade angle adjustment reference in place according to the preset blade angle outside the wind tunnel. Then, the blade angle adjustment reference is directly placed on the propeller hub of the wind tunnel test model. The blade angle can be directly adjusted on the wind tunnel test model so that the surface of the blade is in contact with the second reference surface of the blade angle adjustment reference to complete the blade angle adjustment. There is no need to disassemble and reinstall the model propeller system, which can improve the test efficiency of wind tunnel test.

[0014] 2) After the blade angle adjustment device is set, the blade angle can be checked at any time during the wind tunnel test. If there is any deviation, it can be easily adjusted to ensure that the blade angle is always at the correct angle during the wind tunnel test and to ensure the accuracy of the data.

[0015] 3) The blade angle adjustment device of this application has a simple structure, is easy to use, and has widespread application value.

[0016] The present application will be further described in detail below with reference to the accompanying drawings of the embodiments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a propeller blade angle adjustment device for wind tunnel testing.

[0018] Figure 2This is a schematic diagram of the blade angle adjustment base.

[0019] Figure 3 This is a side view of the reference for blade angle measurement.

[0020] Figure 4 Top view of the blade angle measurement reference.

[0021] Figure 5 This is a side view of the blade angle adjustment reference.

[0022] Figure 6 A schematic diagram showing the blade angle adjustment reference being erected.

[0023] Figure 7 This is a schematic diagram of the method for adjusting the propeller blade angle in wind tunnel testing.

[0024] The numbers in the diagram are explained as follows: 1 Adjustment platform, 2 Hub simulation block, 3 Blade angle adjustment reference, 4 Connecting block, 5 Blade angle setting block, 6 First measuring block, 7 Second measuring block, 8 Adjustment disc, 9 Blade angle measurement reference mounting base, 10 Horizontal adjustment screw, 11 First reference surface, 12 Second reference surface, 13 Clamping part, 14 Clamping screw, 15 First measuring surface, 16 Second measuring surface, 17 Measuring reference surface, 18 Concentric shaft, 19 Blade, 20 Hub. Detailed Implementation

[0025] Referring to the attached figures, the wind tunnel test propeller blade angle adjustment device of this application includes a blade angle adjustment base, a blade angle adjustment reference, and a blade angle measurement reference.

[0026] Blade angle adjustment base such as Figure 2 As shown, it includes an adjustment platform 1, on which a hub simulation block 2 and a blade angle measurement reference mounting base 9 are provided. The hub simulation block 2 has a hub simulation surface, which is perpendicular to the adjustment platform 1. In order to ensure that the adjustment platform 1 is in a horizontal state during operation, horizontal adjustment screws 10 for leveling are also provided at both ends of the adjustment platform 1.

[0027] The blade angle adjustment reference is as follows: Figure 5 , Figure 6 As shown. The blade angle adjustment reference 3 can be placed between the hub simulation block 2 and the blade angle measurement reference mounting base 9 of the adjustment platform 1. The body of the blade angle adjustment reference 3 is a plate-like structure. At the lower end of the blade angle adjustment reference 3, there is a first reference surface 11, which is an arc-shaped surface. The curvature of the arc-shaped surface is consistent with the curvature of the hub simulation surface on the hub simulation block 2. At the upper end of the blade angle adjustment reference 3, there is a second reference surface 12, which is a lateral plane. The angle between the second reference surface 12 and the body of the blade angle adjustment reference 3 is adjustable. The second reference surface 12 matches the surface of the blade angle measurement position.

[0028] To facilitate adjustment of the angle between the second reference surface 12 and the blade angle adjustment reference 3, in practice, a blade angle setting block 5 is connected to the upper end of the blade angle adjustment reference 3 via a connecting block 4. The blade angle setting block 5 is a semi-circular flat plate structure, with the second reference surface 12 on one side. An arc-shaped groove is provided on the blade angle setting block 5, and a pin connects the blade angle setting block 5 to the connecting block 4 through the arc-shaped groove. The connecting block 4 is fixed to the upper end of the blade angle adjustment reference 3, allowing the blade angle setting block 5 to rotate relative to the pin along the arc-shaped groove to adjust the angle between the second reference surface 12 and the blade angle adjustment reference 3. A clamping member 13 is provided between the surface of the blade angle setting block and the pin, which can fix and clamp the blade angle setting block 5. An angle indicator scale line is also provided on the surface of the blade angle setting block 5, and this angle indicator scale line coincides with the angle between the second reference surface 12 and the blade angle adjustment reference 3.

[0029] The blade angle measurement reference is as follows: Figure 4 , Figure 5 As shown, the blade angle measuring reference body contains a measuring reference surface 17 and one or two measuring surfaces. There is a pre-offset angle between the measuring reference surface 17 and the measuring surfaces. The blade angle measuring reference body is hinged to the blade angle measuring reference mounting base 9. The measuring reference surface 17 matches the second reference surface 12 of the blade angle adjustment reference 3.

[0030] The blade angle measurement reference in this embodiment includes a first measuring block 6 and a second measuring block 7. The first measuring block 6 and the second measuring block 7 are parallel and coaxially connected. The first measuring block 6 has a measuring reference surface 17 and a first measuring surface 15. There is a pre-offset angle between the measuring reference surface 17 and the first measuring surface 15. The second measuring block 7 has a second measuring surface 16. The second measuring surface 16 is parallel to the measuring reference surface 17. The concentric shaft 18 between the first measuring block 6 and the second measuring block 7 is hinged to the blade angle measurement reference mounting base 9.

[0031] To facilitate adjustment of the angle between the first or second measuring surface and the adjustment platform 1, a parallel and coaxially connected adjustment disc 8 is provided between the first measuring block 6 and the second measuring block 7. The adjustment disc 8 is provided with an arc-shaped slide rail. The adjustment disc is also connected to the blade angle measuring reference mounting base 9 through the arc-shaped slide rail and the clamping screw 14. The adjustment disc 8 can drive the first measuring block 6 and the second measuring block 7 to rotate. The arc-shaped slide rail and the clamping screw 14 of the adjustment disc 8 can limit the rotation of the first measuring block 6 and the second measuring block 7.

[0032] Since the blade angle is measured at 0.7 times the blade rotation radius, the vertical distance between the center of the first reference surface 11 at the lower end of the blade angle adjustment reference 3 and the second reference surface 12 is 0.7 times the blade rotation radius.

[0033] When adjusting the blade angle using the wind tunnel test propeller blade angle adjustment device of this application, firstly, outside the wind tunnel, the first measuring surface 15 or the second measuring surface 16 of the blade angle measurement reference needs to be adjusted relative to the adjustment platform 1 to match the preset blade angle and then fixed; then, the blade angle adjustment reference 3 is placed on the adjustment platform 1 of the blade angle adjustment base, so that the first reference surface 11 is attached to the hub simulation surface of the hub simulation block 2, and the second reference surface 12 at its upper end is attached to the measuring reference surface 17 of the blade angle measurement reference. The blade angle setting block 5 is pressed onto the connecting block 4 by the clamping member 13, keeping the second reference surface 12 relative to the body of the blade angle adjustment reference 3 unchanged; then, the blade angle adjustment reference 3 is placed on the propeller hub 20 inside the wind tunnel, such as... Figure 7 As shown, the first reference surface 11 at the lower end of the blade angle adjustment reference 3 is made to fit against the surface of the hub 20. The blade angle of the propeller blade 19 is adjusted so that the surface of the blade 19 fits against the second reference surface 12 at the upper end of the blade angle adjustment reference 3, thereby fixing the relative position of the blade 19 and the hub 20. The same method is used to adjust the blade angle of all blades 19.

[0034] In this embodiment, the adjustment platform 1 provides a reference plane for the entire device. Three M8 hexagonal headstock leveling screws 10 are located on its surface to adjust and keep the adjustment platform 1 level. The rotor hub simulation block 2 is positioned by pins and fixed to the adjustment platform 1 with screws. The radius of its simulated rotor hub arc surface is 80mm, and the center of the arc surface is the center of the simulated propeller disk. The blade angle adjustment reference 3 is placed on the adjustment platform 1. Its lower end, the first reference surface 11, is in contact with the arc surface on the rotor hub simulation block 2. Its upper end is connected to a connecting block 4 by screws. This connecting block is the mounting base for the blade angle setting block 5. The distance between the upper surface of the connecting block 4 and the center of the arc surface of the rotor hub simulation block 2 is 255mm, which is 70% of the propeller radius. The blade angle setting block 5 is connected to the connecting block 4 via a pin. It can rotate around its center through an arc-shaped groove to change the angle between the second reference surface 12 and the plane of the adjustment platform 1. After the angle is set, the blade angle setting block 5 can be reliably locked by the clamping member 13. In this case, an inclinometer is used to measure the angle between the first measuring surface 15 or the second measuring surface 16 and the plane of the adjustment platform 1. Since the optimal measurement range of the inclinometer is ±45°, and the blade angle setting range in this case is -15° to 100°, two measuring blocks are set. The first measuring surface 15 on the first measuring block 6 has a preset angle of 55° with the measuring reference surface 17 for measuring blade angles from 45° to 100°. The second measuring surface 16 on the second measuring block 7 is parallel to the measuring reference surface 17 and is used for setting blade angles from -15° to 45°. The blade angle measuring reference mounting base 9 is used to install the blade angle measuring reference. It is positioned by pins and fixed to the adjustment platform 1 with screws.

[0035] One implementation process for adjusting the blade angle is as follows: 1) Place the adjustment platform 1 on the operating platform of the wind tunnel operating room, and adjust the adjustment platform 1 to be horizontal using the horizontal adjustment screw 10; 2) Rotate the adjustment disk 8 to adjust the angle of the first measuring surface 15 of the blade angle, and use an inclinometer to measure the angle of the first measuring surface 15 relative to the plane of the adjustment platform 1. After reaching the required angle, use the clamping screw 14 to lock the blade angle measurement reference; 3) Place the blade angle adjustment reference 3 on the adjustment platform 1, release the clamping part 13 on the pin, so that the blade angle setting block 5 can rotate freely, so that the first reference surface 11 at the lower end of the blade angle adjustment reference 3 is in contact with the arc surface of the blade hub simulation block 2, adjust the angle of the blade angle setting block 5, so that the second reference surface 12 on the blade angle setting block 5 is in contact with the measuring reference surface 17 at the lower part of the first measuring block 6, and lock the blade angle setting block 5 with the clamping part 13; 4) Place the blade angle adjustment reference 3 (see Figure 5 Move it into the wind tunnel and place it in the corresponding position on the propeller hub (see...). Figure 7 5) Unlock the blade angle locking screw of the blade 19 on the rotor hub 20, adjust the angle of the propeller blade 19 so that the surface of the blade 19 is in contact with the second reference surface 12 of the blade angle setting block 5, and then lock the blade angle locking screw to obtain the required blade angle; 6) Repeat step 5 until the blade angle of all blades is set.

[0036] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope defined in the claims of the present invention.

Claims

1. A wind tunnel test propeller blade angle adjustment device, wherein the blades are connected to the hub, characterized in that, The blade angle adjustment device includes a blade angle adjustment base, a blade angle adjustment reference, and a blade angle measurement reference. The blade angle adjustment base includes an adjustment platform, on which a hub simulation block and a blade angle measurement reference mounting base are provided. The hub simulation block has a hub simulation surface, which is perpendicular to the adjustment platform. The blade angle adjustment reference can be placed between the hub simulation block and the blade angle measurement reference mounting base on the adjustment platform. The blade angle measurement reference includes a first measuring block and a second measuring block, which are parallel and coaxially connected. The first measuring block has a measurement reference surface and a first measuring surface, with a pre-offset angle between them. The second measuring block has a second measuring surface, which is parallel to the measurement reference surface. The connecting shaft between the second measuring blocks is hinged to the blade angle measuring reference mounting base. The blade angle adjusting reference body is a plate-shaped structure. At the lower end of the blade angle adjusting reference is a first reference surface, which is an arc-shaped surface. The curvature of the arc-shaped surface is consistent with the curvature of the blade hub simulation surface on the blade hub simulation block. At the upper end of the blade angle adjusting reference is a second reference surface, which is a lateral plane. The angle between the second reference surface and the blade angle adjusting reference body is adjustable. The second reference surface matches the surface of the blade angle measurement position. The blade angle measuring reference body contains a measuring reference surface and a measuring surface. There is a pre-offset angle between the measuring reference surface and the measuring surface. The blade angle measuring reference body is hinged to the blade angle measuring reference mounting base, and the measuring reference surface matches the second reference surface of the blade angle adjusting reference.

2. The wind tunnel test propeller blade angle adjustment device as described in claim 1, characterized in that, The vertical distance between the center of the first reference plane and the second reference plane is 0.7 times the blade rotation radius.

3. The wind tunnel test propeller blade angle adjustment device as described in claim 1 or 2, characterized in that, The upper end of the blade angle adjustment reference body is connected to a blade angle setting block via a connecting block. The blade angle setting block is a semi-circular flat plate structure. One side of the blade angle setting block is a second reference surface. The blade angle setting block is provided with an arc groove. A pin connects the blade angle setting block to the connecting block through the arc groove. The connecting block is fixed to the upper end of the blade angle adjustment reference body, so that the blade angle setting block can rotate in a plane relative to the pin along the arc groove to adjust the angle between the second reference surface and the blade angle adjustment reference body.

4. The wind tunnel test propeller blade angle adjustment device as described in claim 3, characterized in that, A clamping element is provided between the surface of the blade angle setting block and the pin shaft. The clamping element can fix and press the blade angle setting block. An angle indicator scale line is also provided on the surface of the blade angle setting block. The angle indicator scale line is consistent with the angle between the second reference surface and the blade angle adjustment reference body.

5. The wind tunnel test propeller blade angle adjustment device as described in claim 1, characterized in that, A parallel and coaxially connected adjustment plate is provided between the first and second measuring blocks. The adjustment plate has an arc-shaped slide. The adjustment plate is also connected to the blade angle measuring reference mounting base through the arc-shaped slide and the clamping screw. The adjustment plate can drive the first and second measuring blocks to rotate. The arc-shaped slide and the clamping screw of the adjustment plate can limit the rotation of the first and second measuring blocks.

6. A method for adjusting the blade angle of a propeller based on the wind tunnel test propeller blade angle adjustment device according to any one of claims 1-5, characterized in that, The process includes the following steps: 1) Adjust the first or second measuring surface of the blade angle measurement reference relative to the adjustment platform until it matches the preset blade angle and then fix it; 2) Place the blade angle adjustment reference on the adjustment platform of the blade angle adjustment base, so that the first reference surface is attached to the blade hub simulation surface of the blade hub simulation block, and the second reference surface at its upper end is attached to the measuring reference surface of the blade angle measurement reference, keeping the second reference surface relative to the blade angle adjustment reference body unchanged; 3) Place the blade angle adjustment reference on the propeller hub, so that the first reference surface at the lower end of the blade angle adjustment reference is attached to the surface of the blade hub, and adjust the blade angle of the propeller so that the blade surface is attached to the second reference surface at the upper end of the blade angle adjustment reference, thereby fixing the relative position of the blade and the blade hub; 4) Use the same method to complete the adjustment of the blade angle of all blades.

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