An aerodynamic force test system and method for simulating the rotating state of a propeller

Abstract

An aerodynamic force test system and method for simulating the rotating state of a propeller. The cavity structure (2) includes left and right semi-circular rotating bodies arranged symmetrically. One end of the left semi-circular rotating body serves as the air outlet and is connected to the air inlet of the contraction section (3). The contraction section (3) is a hollow cavity with a gradually decreasing cross-section. The air outlet of the contraction section (3) is connected to the air inlet at one end of the test section (4). The test section (4) is a hollow cavity. The air outlet at the other end of the test section (4) is connected to the air inlet of the return section (6). The testing device (5) carries the propeller. The end with a smaller cross-section of the return section (6) is connected to the air outlet of the test section (4), and the end with a larger cross-section is connected to the air inlet of the right semi-circular rotating body. The air outlet at the other end of the right semi-circular rotating body is connected to the air inlet at one end of the buffer section (7). The other end of the buffer section (7) serves as the air outlet and is connected to the air inlet at the other end of the left semi-circular rotating body. The present invention is easy to implement, has low cost, high efficiency, and high precision.

Description

Technical Field

[0001] The present invention belongs to the technical field of wind tunnel tests, and particularly relates to an aerodynamic force test system and method for simulating the rotating state of a propeller. Background Art

[0002] The propeller is an important component and core device of a propeller-powered aircraft. It converts the rotational power of the engine into the power for the aircraft to fly by rotating the propeller blades in the air, thereby realizing functions such as takeoff, cruise, and landing during the flight profile of the aircraft. Compared with the jet-powered propulsion system, the propeller-powered propulsion system has the advantages of high efficiency, long range, short takeoff and landing, and low cost. In order to obtain accurate aerodynamic performance of the propeller and the propeller-engine matching characteristics, it is usually necessary to simulate the actual working state of the propeller and measure the thrust and torque of the propeller under corresponding working conditions.

[0003] The main traditional means of realizing propeller simulation measurement all require the propeller to rotate, and then measure the thrust and torque of the propeller through a high-precision multi-component force balance, so as to calculate the propeller efficiency. However, the area of the propeller increases in the rotating state, and the requirements for the size of the wind tunnel to ensure a uniform flow field are relatively high. Most wind tunnels are difficult to meet the test requirements of large-size propellers; the scaled-down test can be carried out in a small wind tunnel, but it is impossible to ensure geometric similarity, kinematic similarity, and dynamic similarity at the same time. It is also necessary to ignore the influence of the Reynolds number and Mach number, and at the same time, it cannot meet the deformation similarity criterion, which has a great impact on the accuracy of the measurement results; while the flight test not only requires the cooperation of the whole machine, but also requires supporting telemetry acquisition equipment, and the test cost is high and the risk is large, which is not applicable during the development stage.

[0004] According to the similarity criterion of experimental fluid mechanics, for geometrically similar propellers, kinematic similarity requires that the airflow velocity field around the propeller be similar, that is, to ensure that in the flow field around the propeller, the velocity magnitudes at corresponding points are the same and the directions are the same. In view of this, an aerodynamic force test system is needed. Summary of the Invention

[0005] The purpose of the present invention is to solve the deficiencies of the existing propeller wind tunnel tests, and propose an aerodynamic force test system and method for simulating the rotating state of a propeller, which is based on the oncoming flow conditions of a variable cross-section shear layer to simulate the aerodynamic force in the rotating state of the propeller for testing, solves the technical problem of simulating the rotating state of the propeller under the oncoming flow conditions of a variable cross-section shear layer for aerodynamic force testing, and realizes the flow field simulation and high-precision measurement of aerodynamic force in the rotating state of the propeller.

[0006] The present invention proposes an aerodynamic force test system for simulating the rotating state of a propeller, including: a tunnel body structure, a contraction section, a test section, a test device, a return section, and a buffer section; wherein,

[0007] The cavity structure includes a left semi-circular rotating body and a right semi-circular rotating body arranged symmetrically left and right; one end of the left semi-circular rotating body serves as an air outlet and is connected to the air inlet of the contraction section.

[0008] The contraction section is a hollow cavity with a gradually decreasing cross-section. The end with a larger cross-sectional area of the contraction section serves as the air inlet, and the end with a smaller cross-sectional area serves as the air outlet; the air outlet of the contraction section is connected to the air inlet at one end of the test section.

[0009] The test section is a hollow cavity, and a propeller and a test carrier are installed inside the cavity; the air outlet at the other end of the test section is connected to the air inlet of the return section.

[0010] The test device carries the propeller, adjusts the pitch angle of the propeller, and measures the aerodynamic data of the propeller.

[0011] The return section is a sealed expanding section with rectangular interfaces at both ends. The end with a smaller cross-section of the return section serves as the air inlet and is connected to the air outlet of the test section; the end with a larger cross-section of the return section serves as the air outlet and is connected to the air inlet of the right semi-circular rotating body; the air outlet at the other end of the right semi-circular rotating body is connected to the air inlet at one end of the buffer section.

[0012] The buffer section is a hollow cuboid, and multiple layers of damping turbulence nets are installed inside the buffer section. The other end of the buffer section serves as the air outlet and is connected to the air inlet at the other end of the left semi-circular rotating body.

[0013] Further, when the propeller is a single-segment airfoil, the test device includes: a support structure, a pitch angle adjustment device, a force measuring balance, and a transfer support rod.

[0014] The pitch angle adjustment device is provided on the support structure. The extended section of the adjustment end of the pitch angle adjustment device is connected to one end of the force measuring balance. The other end of the force measuring balance is connected to one end of the transfer support rod, and the other end of the transfer support rod is connected to the single-segment airfoil.

[0015] Further, when the propeller is a multi-segment airfoil, the test device includes: a support structure, a pitch angle adjustment device, a force measuring balance, a transfer support rod, a variable pitch motor, and a cantilever support structure; the pitch angle adjustment device is installed on the support structure. The cantilever of the adjustment end of the pitch angle adjustment device passes through the cantilever support structure and installs the variable pitch motor. The output shaft of the variable pitch motor enters the interior of the test section. The end of the output shaft is connected to the multi-segment airfoil through a series combination of a force measuring balance and a transfer support rod. A series combination of a force measuring balance and a transfer support rod is provided between each segment of the multi-segment airfoil.

[0016] Further, when the propeller has a multi-segment airfoil, the contraction section further includes a plurality of sub-air vents formed by dividing with a plurality of comb-shaped arranged air guide plates; the number of the sub-air vents corresponds to the number of the multi-segment airfoils, and each sub-air vent corresponds to one segment of the airfoil.

[0017] Further, the cross-sectional areas of the inlets and outlets of the respective sub-air vents satisfy the following conditions:

[0018] A1*V1 = A2*V2,

[0019] wherein, A1 is the cross-sectional area of the inlet of the sub-air vent, A2 is the cross-sectional area of the outlet of the sub-air vent, V1 is the air flow velocity at the inlet of the sub-air vent, and V2 is the air flow velocity at the outlet of the sub-air vent; and the cross-sectional width of the outlet is the same as the width of the corresponding segmented airfoil.

[0020] Further, it further includes a control system, and the control system adjusts the flow field parameters of the left semi-circular rotating body and controls the flow field within the left semi-circular rotating body according to the flow field parameters, specifically including:

[0021] For the propeller airfoil, by controlling the oncoming flow pressure P0, the oncoming flow temperature T, and the inlet flow rate Q of the air source entering the flow field, and adjusting the back pressure P of the oncoming flow, the flow field parameters are adjusted, and the flow field parameters satisfy the following constraint conditions:

[0022]

[0023]

[0024] wherein, Re is the Reynolds number of the flow field, V is the oncoming flow air velocity, μ is the dynamic viscosity coefficient, and D is the chord length of the propeller airfoil.

[0025] Further, both ends of the buffer section are respectively provided with connection sections having a gradually changing cross-section rectangle, the ends with smaller cross-sectional areas of the two connection sections are respectively connected to both ends of the buffer section, the end with a larger cross-sectional area of one connection section is connected to the air outlet end of the right semi-circular rotating body, and the end with a larger cross-sectional area of the other connection section is connected to the air inlet of the left semi-circular rotating body;

[0026] The flow field buffer device includes 5 - 10 sections of damping spoiler nets, and the thickness of each layer of damping spoiler net is at least 10 cm;

[0027] Both ends of the return flow section are rectangular, and the outer wall surface of the return flow section is gradually transitioned with a quadratic curve cross-section, and the outer wall has an equal thickness.

[0028] The present invention also provides an aerodynamic force test method for simulating the rotating state of a propeller, including:

[0029] S1. Generate a corresponding flow field in the left semi-circular rotating body of the cavity structure according to the flow field parameters;

[0030] S2. Determine the initial pitch angle and oncoming flow velocity of the propeller according to the airfoil of the propeller to be measured, and use the testing device to conduct aerodynamic tests on the propeller at different oncoming flow velocities, different pressures, and different pitch angles;

[0031] S3. Collect the aerodynamic test data and process the aerodynamic data corresponding to different pitch angles.

[0032] Further, when the propeller to be measured is a single-section airfoil in S2, adjust the pitch angle of the airfoil to be measured through the pitch angle adjusting device of the testing device, and conduct aerodynamic tests through the force measuring balance of the testing device to measure the aerodynamic data of the propeller.

[0033] Further, when the propeller to be measured is a multi-section airfoil in S3, the contraction section further includes multiple sub-air vents formed by dividing multiple comb-shaped arranged air guiding plates;

[0034] Adjust the inlet cross-sectional areas of the multiple air vents to form a simulated rotating flow field with a progressive increase in flow velocity;

[0035] After determining the initial pitch angle of the multi-section airfoil of the propeller, adjust the pitch angle of the airfoil of the propeller through the variable pitch motor of the pitch angle adjusting device of the testing device, and conduct aerodynamic tests on the multi-section airfoil simultaneously through the force measuring balances arranged between adjacent airfoils of the propeller to obtain the aerodynamic data of the propeller;

[0036] Adjust the oncoming flow wind speed, total pressure, and the inlet cross-sectional areas of the multiple air vents to determine the corresponding test conditions, adjust the pitch angle of the multi-section airfoil, and conduct multiple tests to obtain the aerodynamic data of the multi-section airfoil propeller at different pitch angles and under different pitch angles and conditions;

[0037] Sum up the aerodynamic data of the multi-section airfoils corresponding to different pitch angles to obtain the total aerodynamic data.

[0038] Further, in S1, generating a corresponding flow field in the left semi-circular rotating body of the cavity structure according to the flow field parameters specifically includes:

[0039] For the airfoil with a chord length D, adjust the flow field parameters by controlling the oncoming flow pressure P0, oncoming flow temperature T, and inlet flow rate Q of the air source entering the flow field, and adjusting the back pressure P of the oncoming flow. The flow field parameters satisfy the following constraint conditions:

[0040]

[0041]

[0042] Wherein, Re is the Reynolds number of the flow field, V is the oncoming flow velocity, and μ is the dynamic viscosity coefficient.

[0043] The advantages of the present invention compared with the prior art are as follows:

[0044] (1) The present invention is easy to implement, has low cost and high efficiency. In the present invention, the aerodynamic force test system and equipment for simulating the rotating state of a propeller based on the oncoming flow conditions of a variable cross-section shear layer do not require the use of a large-scale wind tunnel to test the propeller, and the required wind tunnel size for the propeller under the rotating state is 50% smaller. At the same time, the present invention also does not require a high-power engine / motor to drive the propeller to rotate. Only the aerodynamic force of a single blade is measured in segments in a small-scale wind tunnel. It has the advantages of a wide range of applicable propellers, a relatively simple test system, low cost and high efficiency. It is more prominent than the advantages of flight tests, is easier to implement, and has higher safety.

[0045] (2) The present invention has high precision and obvious comparison effects. The test system adopted in the present invention can ensure geometric similarity, kinematic similarity and dynamic similarity at the same time compared with the traditional wind tunnel scale-down test. Compared with the full-scale wind tunnel test, the influence of the wind tunnel wall effect on the single-blade force measurement test is smaller, and the measurement accuracy is higher. The comparison effects for the optimization, improvement and verification of the blade are more obvious. Description of the Drawings

[0046] Figure 1 It is a flowchart of the method provided by the invention;

[0047] Figure 2 It is a schematic diagram of the system composition and layout of the present invention;

[0048] Figure 3 It is a schematic diagram of the test arrangement plan and layout of the single-section airfoil of the present invention;

[0049] Figure 4 It is a schematic diagram of the connection method between the single-section airfoil balance and the strut of the present invention;

[0050] Figure 5 It is a schematic diagram of the layout of the test arrangement plan of the multi-section airfoil of the present invention;

[0051] Figure 6 It is a schematic diagram of the pitch angle adjustment device and connection method of the multi-section airfoil of the present invention;

[0052] Figure 7 It is a schematic diagram of the connection method between the multi-section airfoil balance and the strut of the present invention.

[0053] 1. Control system, 2. Cavity structure including left and right semi-circular rotors, 3. Contraction section, 4. Test section, 5. Testing device, 6. Return flow section, 7. Buffer section, 8. Support structure, 9. Pitch angle adjustment device, 10. Force measuring balance, 11. Single-section airfoil, 12. Adapter strut, 13. Variable cross-section shear type contraction section, 14. Multi-section airfoil, 15. First section airfoil, 16. Second section airfoil, 17. Third section airfoil, 18. Fourth section airfoil, 19. Fifth section airfoil, 20. Variable pitch motor, 21. Cantilever support. Specific implementation mode

[0054] The present invention provides an aerodynamic force test system and method for simulating the rotating state of a propeller. As Figure 2 shown, the test system includes: a control system 1, a cavity structure 2, a contraction section 3, a test section 4, a testing device 5, a return flow section 6, and a buffer section 7.

[0055] The cavity structure 2 includes a pair of semi-circular rotors arranged symmetrically on the left and right; the air outlet of the left semi-circular rotor is connected to the air inlet of the contraction section 3, the air outlet at the other end of the contraction section 3 is connected to the air inlet of the test section 4, the air outlet at the other end of the test section 4 is connected to the air inlet of the return flow section 6, the air outlet at the other end of the return flow section 6 is connected to the air inlet of the right semi-circular rotor, the air outlet of the right semi-circular rotor is connected to the air inlet of the buffer section 7, and the air outlet at the other end of the buffer section 7 is connected to the air inlet at the other end of the left semi-circular rotor. The connection between the left and right semi-circular rotors, the contraction section 3, the test section 4, the testing device 5, the return flow section 6, and the buffer section 7 is airtight.

[0056] The control system 1 of the aerodynamic force test system is used to adjust the flow field parameters of the cavity structure, and adjusts the flow field parameters by controlling the high-pressure air source entering the flow field, the inlet flow rate, and the ejector, and it includes the total temperature T, the total pressure P, and the flow rate Q, etc. The control system 1 generates a flow field inside the cavity structure according to the flow field parameters to provide a flow field environment for the test.

[0057] Controlling the flow field inside the left semi-circular rotor according to the flow field parameters specifically includes: for the propeller airfoil, by controlling the oncoming flow pressure P0, the oncoming flow temperature T, and the inlet flow rate Q of the air source entering the flow field, and adjusting the back pressure P of the oncoming flow to achieve flow field parameter adjustment, and the flow field parameters satisfy the following constraint conditions:

[0058]

[0059]

[0060] where Re is the Reynolds number of the flow field, V is the oncoming flow velocity, μ is the dynamic viscosity coefficient, and D is the chord length of the propeller airfoil.

[0061] The cavity structure 2 is the main load-bearing structure for the circulating flow of air. Its segmented structure is a semi-circular rotating body arranged symmetrically on the left and right. The air outlet of the left semi-circular rotating body is hermetically connected to the inlet of the expansion end of the contraction section 3 of the variable cross-section structure. The air outlet of the contraction end of the contraction section 3 is directly connected to the inlet of the test section 4 through a flange sealing method, ensuring that the air circulates under a constant-pressure sealed state. Among them, the contraction section 3 is a continuously variable cross-section rectangular structure that can change the flow field parameters in front of the test section 4. By contracting the cross-sectional area, the flow field velocity at the outlet can be further increased.

[0062] The test section 4 is arranged at the end of the contraction section 3 and is hermetically and directly connected to the end of the contraction section 3 of the cavity structure at one end, and the air outlet at the other end is hermetically connected to the inlet of the return section 6. It is a long straight rectangular device for placing the object to be measured and the test system. The side wall of the test section 4 has an opening, and the object to be measured is arranged at the center of the test section by inserting it into the opening.

[0063] The test device 5 includes the object to be measured, a support mechanism 8, a pitch angle adjustment mechanism 9, a high-precision multi-component force measuring balance 10 and its data acquisition device, and is used to measure the aerodynamic force data of the object to be measured under different working conditions.

[0064] The return section 6 is a rectangular expansion section with a variable cross-section. Its contraction end is connected to the end of the test section 4, and the expansion end is connected to one end of the inlet of the right semi-circular rotating body. The air outlet at the other end of the right semi-circular rotating body is connected to one end of the inlet of the buffer section 7 through a variable cross-section rectangular contraction section, and is used to recover the decelerated air flow after passing through the model. The two ends of the return section 6 are rectangular, and the outer wall surface between the two ends gradually transitions with a quadratic curve cross-section, and the outer wall has an equal thickness.

[0065] The buffer section 7 is a hollow cuboid with a flow field buffer device inside. The air outlet at the other end is connected to the inlet of the other end of the left semi-circular rotating body through a variable cross-section rectangular expansion section. A multi-layer damping turbulence net is installed inside the buffer section 7 as a flow field buffer device to buffer the turbulent flow field and improve the flow field uniformity. The flow field buffer device includes 5 - 10 sections of damping turbulence nets, and the thickness of each layer of damping turbulence net is at least 10 cm.

[0066] This aerodynamic force test system can test the propeller models to be measured of single-section airfoils and multi-section airfoils respectively.

[0067] Such as Figures 3 - 4As shown in the figure, when the model to be tested is a single-segment airfoil, the test device 5 includes: a support structure 8, a pitch angle adjustment device 9, and a force measuring balance 10. The pitch angle adjustment device 9 is installed on the support structure 8. The extended section of the adjustment end of the pitch angle adjustment device 9 enters the interior of the test section 4 through a hole on the test section 4 and is connected to one end of the force measuring balance 10. The other end of the force measuring balance 10 is connected to the test airfoil 11. The force measuring balance 10 is used to measure the aerodynamic data of the object to be tested, such as thrust, torque, etc. Preferably, a high-precision multi-component force measuring balance 10 is used, which is connected to the single-segment airfoil 11 through an adapter strut 12. The adapter strut 12 is used to fix, support, and connect the pitch angle adjustment device 9. The pitch angle adjustment device 9 is used to quantitatively adjust the pitch angle of the airfoil 11 to be tested.

[0068] As Figures 5 - 6 shown in the figure, when the model to be tested is a multi-segment airfoil 14, the conventional contraction section of the single-segment airfoil is replaced with a variable cross-section shear-type contraction section 13. The flow field at the front end of the model to be tested is affected by the variable cross-section shear-type contraction section and becomes a simulated rotating flow field with progressive acceleration. The ventilation outlet of the variable cross-section shear-type contraction section 13 is formed by dividing into multiple sub-ventilation outlets by a plurality of comb-shaped arranged air guide plates. The inlet area of the ventilation port of the variable cross-section shear-type contraction section can be adjusted. In one embodiment, the multi-segment airfoil 14 is divided into five sub-airfoils, and the sub-ventilation outlets of the variable cross-section shear-type contraction section 13 correspond to the first-segment airfoil 15, the second-segment airfoil 16, the third-segment airfoil 17, the fourth-segment airfoil 18, and the fifth-segment airfoil 19 respectively.

[0069] The cross-sectional areas of the inlets and outlets of the respective sub-ventilation ports satisfy the following conditions:

[0070] A1*V1 = A2*V2,

[0071] where A1 is the cross-sectional area of the inlet of the sub-ventilation port, A2 is the cross-sectional area of the outlet of the sub-ventilation port, V1 is the air flow velocity at the inlet of the sub-ventilation port, and V2 is the air flow velocity at the outlet of the sub-ventilation port; and the cross-sectional width of the outlet is the same as the width of the corresponding segmented airfoil.

[0072] The test device 5 includes: a support structure 8, a pitch angle adjustment device 9, and a force measuring balance 10; the pitch angle adjustment device 9 is installed on the support structure 8. The cantilever of the adjustment end of the pitch angle adjustment device 9 passes through the cantilever support structure 21 and installs a variable pitch motor 20. The variable pitch motor 20 is used to drive the connecting strut to change the rotation angle of the overall mechanism so as to achieve pitch angle adjustment. The output shaft of the variable pitch motor 20 enters the interior of the test section 4 through a hole on the test section. The end of the output shaft is successively connected to the multi-segment airfoil, such as the first-segment airfoil 15, the second-segment airfoil 16, the third-segment airfoil 17, the fourth-segment airfoil 18, and the fifth-segment airfoil 19. They also change their pitch angle positions by driving the connecting strut by the variable pitch motor, and can measure the five-segment airfoil simultaneously in one test.

[0073] The number of the sub-outlet ports corresponds to the number of the multi-segment airfoils, and the position of each outlet port corresponds to a corresponding rotating propeller airfoil segment for testing.

[0074] As Figure 7 shown, a dynamometer 10 can be arranged between the airfoil segments of the multi-segment airfoil.

[0075] As Figure 2 shown, a symmetric semi-circular rotary body is arranged between the return flow section 6 and the buffer section 7 for connecting the return flow section 6 and the buffer section 7. At both ends of the buffer section 7, rectangular connecting sections with variable cross-sections are respectively installed. The expansion end of the variable cross-section rectangle is connected to one end of the symmetric semi-circular rotary body, and the contraction section of the variable cross-section rectangle is connected to both ends of the buffer section 7.

[0076] The present invention also provides an aerodynamic force test method for simulating the rotating state of a propeller. As Figure 1 shown, the steps include:

[0077] (1) Build the Figure 2 shown test system, control the flow field parameters through the control system, and calibrate the flow field parameters on the premise that the flow field uniformity and airtightness meet the requirements.

[0078] (2) When the airfoil to be tested is a single-segment airfoil, as Figure 3 and 4 install and test the model. The single-segment airfoil represents the average morphology and flow field of the corresponding cross-section position of the propeller, decomposes according to the velocity triangle, determines the initial installation angle and the oncoming flow velocity, and selects a high-precision multi-component dynamometer with a full-range coverage according to the results of numerical calculation. Conduct aerodynamic force tests on the single-segment airfoil under different oncoming flow velocities, different pressures, and different pitch angles, and record the experimental data for analysis and calculation of efficiency.

[0079] (3) When the airfoil to be tested is a full-size multi-segment airfoil, as Figure 5 install and test the model. The conventional contraction section includes a variable cross-section shear-type contraction section 13, which has a plurality of sub-ventilation ports formed by dividing a plurality of comb-shaped arranged air guide plates. Design the cross-section of the segmented contraction section according to the sum velocity of the centerline velocity of the segmented anisotropy and the oncoming flow velocity. The product of the inlet area of the corresponding contraction section cross-section and the sum velocity is the same, the outlet areas are consistent, and the outlet parameters of different contraction sections are different. Utilize the mixed shear flow of adjacent contraction section cross-sections to form a gradually changing oncoming flow field, so as to realize a nozzle with a variable oncoming flow velocity.

[0080] (4) Take the variable cross-section contraction section debugged in step (3), replace it into the Figure 5 and connect and debug the simulation test system, as Figure 6Install and debug the first-stage airfoil, second-stage airfoil, third-stage airfoil, fourth-stage airfoil, fifth-stage airfoil, pitch-changing motor, cantilever support, and pitch angle adjustment mechanism in sequence, and drive the pitch-changing motor through the pitch angle adjustment mechanism to adjust the pitch angles of the multi-stage airfoils.

[0081] (5) Decompose the installed and debugged test system and multi-stage airfoils in step (4) according to the velocity triangle, determine the initial installation angle and oncoming flow velocity, and select a high-precision multi-component force balance with a wide range coverage based on the results of numerical calculations. Arrange balances with different ranges between adjacent airfoils, and simultaneously conduct aerodynamic tests on the first to fifth stage airfoils under different oncoming flow velocities, different pressures, and different pitch angles, and record the experimental data for analysis and calculation of efficiency.

[0082] (6) Adjust the oncoming flow wind speed, total pressure, and the variable cross-sectional inlet area of the contraction section to ensure that the similarity conditions for simulating the three-dimensional panel elements satisfy the geometric similarity and kinematic similarity criteria. Adjust the pitch angle position, oncoming flow wind speed, and total pressure in sequence according to the pitch angle information determined in the numerical calculation results, repeat step (5), complete multiple tests, and obtain the aerodynamic results of the multi-stage airfoil propeller under different pitch angles and working conditions.

[0083] (7) After completing the production, connection, and simulation tests of the test model in the above steps, and completing the data acquisition and processing work, finally sum up the aerodynamic data of each segmented airfoil corresponding to different pitch angles, and finally obtain the propeller thrust, torque, and efficiency information corresponding to different working conditions.

[0084] For the airfoil with chord length D, adjust the flow field parameters by controlling the oncoming flow pressure P0, oncoming flow temperature T, and inlet flow rate Q of the air source entering the flow field, and adjusting the back pressure P of the oncoming flow. The flow field parameters satisfy the following constraint conditions:

[0085]

[0086]

[0087] Among them, Re is the Reynolds number of the flow field, V is the oncoming flow velocity, and μ is the dynamic viscosity coefficient.

[0088] The content not described in detail in the specification of the present invention belongs to the common general knowledge of those skilled in the art.

Claims

1. An aerodynamic force test system for simulating the rotating state of a propeller, characterized in that, Comprising: A cavity structure (2), a contraction section (3), a test section (4), a testing device (5), a return section (6) and a buffer section (7); wherein, The cavity structure (2) includes a left semi-circular rotating body and a right semi-circular rotating body arranged symmetrically left and right; one end of the left semi-circular rotating body serves as an air outlet and is connected to the air inlet of the contraction section (3); The contraction section (3) is a hollow cavity with a gradually decreasing cross-section. The end with a larger cross-sectional area of the contraction section (3) serves as the air inlet, and the end with a smaller cross-sectional area serves as the air outlet; the air outlet of the contraction section (3) is connected to the air inlet at one end of the test section (4); The test section (4) is a hollow cavity, and a propeller and a test carrier are installed inside the cavity; the air outlet at the other end of the test section (4) is connected to the air inlet of the return section (6); The testing device (5) carries the propeller, adjusts the pitch angle of the propeller and measures the aerodynamic data of the propeller; The return section (6) is a sealed expanding section body with rectangular interfaces at both ends. The end with a smaller cross-section of the return section (6) serves as the air inlet and is connected to the air outlet of the test section (4); the end with a larger cross-section of the return section (6) serves as the air outlet and is connected to the air inlet of the right semi-circular rotating body; the air outlet at the other end of the right semi-circular rotating body is connected to the air inlet at one end of the buffer section (7); The buffer section (7) is a hollow cuboid, and multiple layers of damping turbulence nets are installed inside the buffer section (7). The other end of the buffer section (7) serves as the air outlet and is connected to the air inlet at the other end of the left semi-circular rotating body; When the propeller is of a multi-segment airfoil type, the contraction section (3) further includes a plurality of sub-air vents formed by dividing with a plurality of comb-shaped arranged air guiding plates; the number of the sub-air vents corresponds to the number of the multi-segment airfoils (14), and each sub-air vent corresponds to one segment of the airfoil; the inlet cross-sectional areas of the plurality of air vents are adjusted to form a simulated rotating flow field with a gradually increasing flow velocity; The cross-sectional areas of the inlets and outlets of each sub-air vent satisfy the following conditions: A1*V1 = A2*V2, wherein, A1 is the inlet cross-sectional area of the sub-air vent, A2 is the outlet cross-sectional area of the sub-air vent, V1 is the air flow velocity at the inlet of the sub-air vent, and V2 is the air flow velocity at the outlet of the sub-air vent; and the cross-sectional width of the outlet is the same as the width of the corresponding segmented airfoil.

2. The system according to claim 1, characterized in that, When the propeller is of a multi-segment airfoil type, the testing device (5) includes: a support structure (8), a pitch angle adjusting device (9), a force measuring balance (10), a connecting support rod (12), a variable pitch motor (20), a cantilever support structure (21); the pitch angle adjusting device (9) is installed on the support structure (8), the cantilever at the adjusting end of the pitch angle adjusting device (9) passes through the cantilever support structure (21) and installs the variable pitch motor (20), the output shaft of the variable pitch motor (20) enters the interior of the test section (4), and the end of the output shaft is connected to the multi-segment airfoil through a series combination of the force measuring balance (10) and the connecting support rod (12). A series combination of the force measuring balance (10) and the connecting support rod (12) is arranged between each segment of the multi-segment airfoil.

3. The system according to claim 1, wherein It further includes a control system (1), and the control system (1) adjusts the flow field parameters of the left semi-circular rotating body and controls the flow field within the left semi-circular rotating body according to the flow field parameters, specifically including: For the propeller airfoil, the flow field parameters are adjusted by controlling the incoming flow pressure P0, incoming flow temperature T, and inlet flow rate Q of the air source entering the flow field, and adjusting the back pressure P of the incoming flow. The flow field parameters satisfy the following constraint conditions: ， Where, Re is the Reynolds number of the flow field, V is the incoming flow air velocity, μ is the dynamic viscosity coefficient, and D is the chord length of the propeller airfoil.

4. The system according to claim 1, characterized in that, Both ends of the buffer section (7) respectively have connecting sections with gradually changing cross-section rectangles. The smaller cross-sectional area ends of the two connecting sections are respectively connected to both ends of the buffer section (7), the larger cross-sectional area end of one connecting section is connected to the air outlet end of the right semi-circular rotating body, and the larger cross-sectional area end of the other connecting section is connected to the air inlet of the left semi-circular rotating body; The buffer section (7) includes multiple layers of damping spoiler nets, and the thickness of each layer of damping spoiler net is at least 10 cm; The interfaces at both ends of the return section (6) are rectangular, and the outer wall surface of the return section (6) is gradually transitioned with a quadratic curve cross-section, and the outer wall has an equal thickness.

5. An aerodynamic force test method for simulating the rotating state of a propeller using the system according to any one of claims 1-4, characterized in that, Including: S1. Generate a corresponding flow field within the left semi-circular rotating body of the cavity structure (2) according to the flow field parameters; S2. Determine the initial pitch angle and incoming flow velocity of the propeller according to the airfoil of the propeller to be tested, and use the testing device to conduct aerodynamic tests on the propeller at different incoming flow velocities, different pressures, and different pitch angles; S3. Collect the aerodynamic test data and process the aerodynamic data corresponding to different pitch angles.

6. The method according to claim 5, wherein When the propeller to be tested is a multi-segment airfoil in S2, the contraction section (3) further includes multiple sub-air vents formed by dividing multiple comb-shaped arranged air guide plates; After determining the initial pitch angle of the multi-segment airfoil of the propeller, adjust the pitch angle of the propeller airfoil through the variable pitch motor (20) of the pitch angle adjustment device (9) of the testing device, and conduct aerodynamic tests on the multi-segment airfoil simultaneously through the force measuring balance (10) arranged between adjacent propeller airfoils to obtain the aerodynamic data of the propeller; Adjust the incoming flow wind speed, total pressure, and the inlet cross-sectional area of the multiple air vents to determine the corresponding test conditions, adjust the pitch angle of the multi-segment airfoil, and conduct multiple tests to obtain the aerodynamic data of the multi-segment airfoil propeller at different pitch angles and under different pitch angles and conditions; Sum the aerodynamic data of the multi-segment airfoils corresponding to different pitch angles to obtain the total aerodynamic data.

7. The method according to claim 5, wherein In S1, generating a corresponding flow field within the left semi-circular rotating body of the cavity structure (2) according to the flow field parameters specifically includes: For the airfoil with chord length D, the flow field parameters are adjusted by controlling the incoming flow pressure P0, incoming flow temperature T, and inlet flow rate Q of the air source entering the flow field, and adjusting the back pressure P of the incoming flow. The flow field parameters satisfy the following constraint conditions: Where, Re is the Reynolds number of the flow field, V is the incoming flow velocity, and μ is the dynamic viscosity coefficient.

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