Rotor wind tunnel test method based on distributed jet active flow control

Abstract

The invention discloses a distributed jet active flow control-based rotor wind tunnel test method, which belongs to the technical field of aviation aerodynamic wind tunnel tests, and comprises the steps of rotor test bed dynamic characteristic test, manipulation matrix calibration, preposed preparation of rotor model dynamic balance and common taper adjustment, and dynamic balance and common taper adjustment. And then hovering and forward flight wind tunnel tests of distributed jet active flow control are carried out in sequence, test data are collected and processed, and the aerodynamic performance of the rotor wing under the condition that jet control exists or not is compared and analyzed. According to the invention, the industrial blank of the lack of a distributed jet active flow control rotor wind tunnel test method is filled, and key technical support is provided for theoretical research, technical optimization and engineering application of the rotor distributed jet active flow control method.

Description

Technical Field

[0001] This invention relates to a rotor wind tunnel testing method based on distributed jet active flow control, belonging to the field of aerodynamic wind tunnel testing technology. Background Technology

[0002] Helicopters, with their superior performance in vertical takeoff and landing, hovering, and low-altitude, low-speed flight, play an irreplaceable role and have broad application prospects in both military and civilian fields. The rotor's motion is highly complex, encompassing not only its own rotational motion and the overall motion of the helicopter, but also the flapping, flaring, and torsional motions of each blade. This results in a rotor flow field exhibiting severe asymmetric, nonlinear, and unsteady characteristics, leading to unique and complex aerodynamic problems. During forward flight, the retreating blades of the rotor experience airflow separation due to excessive angle of attack, causing stall and limiting the helicopter's speed. Distributed jet rotor active flow control technology, as a novel flow control technique, can deflect the separated airflow towards the blade surface, restoring rotor lift and further improving the rotor's aerodynamic characteristics.

[0003] Rotor wind tunnel testing is an important method for studying the application of distributed jet active flow control technology to rotors. Compared with flight testing, wind tunnel testing has the advantages of stable test conditions, low cost, controllable and repeatable test states, making it an ideal way to explore distributed jet active flow control technology. However, at present, a systematic and effective wind tunnel testing method has not yet been developed for rotor wind tunnel testing based on distributed jet active flow control. Summary of the Invention

[0004] This invention aims to solve the problem that there is currently no systematic and effective method for rotor wind tunnel testing based on distributed jet active flow control, and proposes a rotor wind tunnel testing method based on distributed jet active flow control.

[0005] The technical solution of the present invention:

[0006] A rotor wind tunnel testing method based on distributed jet active flow control includes the following steps:

[0007] S1. Rotor test bench dynamic characteristic test, obtain the modal frequencies of each order of the rotor test bench at the center of the rotor hub;

[0008] S2. Rotor control matrix calibration: Construct the conversion relationship between the blade angle of the distributed jet rotor and the rotor control actuator to realize real-time control of the blade pitch angle during blade rotation.

[0009] S3. Dynamic balance adjustment of the distributed jet rotor model: control the distributed jet rotor model to perform dynamic balance adjustment at the working speed until the dynamic balance requirements are met.

[0010] S4. Cone adjustment of distributed jet rotor model: Control the distributed jet rotor model to adjust the cone at the working speed until the cone requirement is met;

[0011] S5. For the rotor test bench and distributed jet rotor model that meet the requirements, conduct distributed jet active flow control hovering wind tunnel test in the test wind tunnel and collect test data. Process the test data and analyze the aerodynamic performance of the distributed jet rotor under hovering working state with and without jet active flow control.

[0012] S6. For the rotor test bench and distributed jet rotor model that meet the requirements, conduct a forward flight wind tunnel test of distributed jet active flow control in the test wind tunnel and collect test data. Process the test data and analyze the aerodynamic performance of the distributed jet rotor under forward flight working conditions with and without jet active flow control.

[0013] Specifically, in step S1, the vibration testing equipment is used to identify the longitudinal and transverse modal frequencies of the rotor test bench at the center of the rotor hub. By adjusting the stiffness device of the rotor test bench, it is ensured that the rotor test bench does not resonate at the operating speed of the distributed jet rotor.

[0014] Specifically, in step S2, the blade pitch angle of the distributed jet rotor is a function of the collective pitch, the periodic pitch, and the blade azimuth angle. By establishing the conversion relationship between the blade pitch angle and the rotor control actuator displacement, a control matrix is ​​constructed to achieve closed-loop control of the blade pitch angle of the distributed jet rotor.

[0015] Specifically, the construction of the control matrix in step S2 includes: moving the rotor control actuator to the target position, measuring the blade pitch angle at different azimuth angles using an angle sensor, and constructing a rotor control matrix based on multiple sets of rotor control actuator displacement and corresponding blade pitch angle data.

[0016] Specifically, the dynamic balance adjustment in step S3 is as follows: after the distributed jet rotor model is installed, the total pitch, longitudinal periodic pitch, and lateral periodic pitch of the distributed jet rotor are controlled to be 0°, and the dynamic balance value of the distributed jet rotor at the working speed is ensured to be less than 0.2IPS by increasing or decreasing the counterweight of the rotor hub arm.

[0017] Specifically, the common conicity adjustment in step S4 is as follows: after the distributed jet rotor model is installed, the total pitch, longitudinal periodic pitch, and lateral periodic pitch of the distributed jet rotor are controlled to be 0°. The height difference between the blades of the distributed jet rotor is less than half the blade thickness at the working speed by finely adjusting the length of the pitch control rod.

[0018] Specifically, in step S5, the distributed jet active flow control hovering wind tunnel test includes the following steps:

[0019] S51. After completing the preparatory work in steps S1, S2, S3, and S4 on the rotor test bench, confirm that each system is in normal condition.

[0020] S52. Keep the main shaft tilt angle of the rotor test bench at 0° and collect the zero reading as the initial reading;

[0021] S53. After starting the distributed jet rotor to the working speed and stabilizing, increase the collective pitch of the distributed jet rotor in steps until the distributed jet rotor tension or tension coefficient is observed to decrease. Perform active flow control of the distributed jet at each collective pitch state, and collect test data with and without jet control respectively. During this period, monitor the balance and vibration parameters in real time to ensure that the parameters are less than the safety threshold.

[0022] S54. After data acquisition is completed, control the rotor collective pitch to 2° and stop the rotor test bench.

[0023] S55. Process the test data collected in step S53 and analyze the aerodynamic performance of the distributed jet rotor under hovering working state with and without active jet flow control.

[0024] Specifically, in step S53, the test data is collected using an azimuth angle synchronous external triggering method, collecting raw data of the distributed jet rotor for a preset number of revolutions, and collecting a preset number of sampling points per revolution; the data processing in step S55 includes multi-revolution averaging and frequency domain transformation of the raw data, and the aerodynamic performance analysis includes the variation law of the distributed jet rotor thrust or thrust coefficient with the collective pitch under and without jet control.

[0025] Specifically, in step S6, the distributed jet active flow control pre-flight wind tunnel test includes the following steps:

[0026] S61. After completing the preparation work of S1, S2, S3 and S4 on the rotor test bench, confirm that the status of each system is normal.

[0027] S62. Collect the initial readings of each main shaft tilt angle of the rotor test bench, and deduct the influence of the self-weight of the part above the balance.

[0028] S63. Adjust the collective pitch of the distributed jet rotor to 2° and start the distributed jet rotor to the operating speed;

[0029] S64. Start the test wind tunnel to the required wind speed. During the wind speed adjustment process, control the rotor control system and main shaft tilting system in real time to complete the forward flight trim of the distributed jet rotor, so that the thrust coefficient of the distributed jet rotor is trimmed to the test value. After the state stabilizes, collect test data under non-controlled conditions.

[0030] S65. Activate the active flow control of the jet and collect test data under control conditions after the state stabilizes.

[0031] S66. Adjust the test wind speed in the test wind tunnel, and repeat steps S64 to S65 until all test wind speed states are completed.

[0032] S67. Adjust the tension coefficient and repeat steps S63 to S66 until all tension coefficient states are completed.

[0033] S68. Control the wind tunnel to stop, and at the same time control the rotor control system to keep the rotor thrust, pitch moment and roll moment within a safe range. When the wind speed is lower than the preset safe wind speed threshold, adjust the rotor collective pitch, cyclic pitch and main shaft tilt angle to a safe zero state, and then control the rotor test bench to stop.

[0034] S69. Process the test data collected in S64~S67 and analyze the aerodynamic performance of the distributed jet rotor under forward flight conditions with and without active jet flow control.

[0035] Specifically, in step S64, the forward flight trim is performed by manipulating the collective pitch of the distributed jet rotor to adjust the thrust coefficient to the experimental value, and the pitch and roll moments of the distributed jet rotor are brought to zero or kept at a preset low value by adjusting the longitudinal and lateral periodic pitch. In steps S64 and S65, the experimental data is collected using an azimuth-synchronized external triggering method, collecting the raw data of the distributed jet rotor for a preset number of revolutions, and collecting a preset number of sampling points per revolution. In step S68, during the wind tunnel shutdown process, the pitch and roll moments of the distributed jet rotor are controlled to remain within a safe threshold. The data processing in step S69 includes multi-revolution averaging and frequency domain transformation of the raw data, and the aerodynamic performance analysis includes the variation law of the lift-to-drag ratio of the distributed jet rotor with and without jet control as a function of the forward ratio.

[0036] The beneficial effects of this invention are:

[0037] This invention establishes for the first time a standard procedure and operating specification for rotor wind tunnel testing based on distributed jet active flow control, filling an industry gap in the lack of such testing methods. It provides key technical support for the theoretical research, technological optimization, and engineering application of rotor distributed jet active flow control methods. Compared to traditional testing methods, it clarifies the key steps of distributed jet active flow control rotor hovering and forward flight wind tunnel testing, reducing the number of invalid tests, lowering the wear and tear on wind tunnel testing equipment and time costs, and shortening the R&D cycle of distributed jet active flow control technology. It can accurately quantify the improvement effect of distributed jet active flow control technology on rotor aerodynamic characteristics, providing reliable methodological guidance for the transformation of this technology from laboratory research to helicopter rotor engineering applications. The invention systematically describes a series of preparatory operations before testing, including rotor test bench dynamic characteristic testing, rotor control matrix calibration, rotor model dynamic balance adjustment, and rotor model conicity adjustment, significantly improving the safety and reliability of this type of testing. Attached Figure Description

[0038] Figure 1 A schematic diagram showing the positional relationship between the test wind tunnel, rotor test rig, and distributed jet rotor;

[0039] Figure 2 A flowchart of a rotor wind tunnel testing method based on distributed jet active flow control;

[0040] In the diagram, 1-test wind tunnel; 2-rotor test bench; 3-distributed jet rotor. Detailed Implementation

[0041] To make the technical solutions and advantages of the embodiments of the present invention clearer, the exemplary embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0042] like Figure 1 , Figure 2 As shown, a rotor wind tunnel testing method based on distributed jet active flow control specifically includes the following steps:

[0043] S1, Rotor test bench 2 dynamic characteristic test, obtain the modal frequencies of each order at the center of the rotor hub of rotor test bench 2;

[0044] Specifically, during rotor testing, the natural frequency of the rotor test bench 2 should be kept from coinciding with the harmonics of the rotor's operating speed, and a certain resonance stability margin should be maintained to prevent resonance. A vibrator is used to excite the rotor test bench 2, and an accelerometer is used to collect vibration signals. Vibration testing equipment is used to identify the longitudinal and transverse modal frequencies of the rotor test bench 2 at the center of the rotor hub. By adjusting the stiffness device of the rotor test bench 2, the dynamic characteristics of the rotor test bench 2 are adjusted to ensure that resonance does not occur at the rotor's operating speed.

[0045] S2. Rotor control matrix calibration: Establish the conversion relationship between blade angle and rotor control actuator to realize real-time feedback of blade pitch angle during blade rotation.

[0046] Specifically, the blade pitch angle of the distributed jet rotor 3 is a function of the collective pitch, the periodic pitch, and the blade azimuth angle. Therefore, before the experiment, it is necessary to establish the conversion relationship between the blade pitch angle and the rotor control actuator displacement, construct the control matrix to realize the blade pitch angle control, and then realize the real-time feedback and closed-loop control of the blade pitch angle during the blade rotation process.

[0047] S3. Dynamic balance adjustment of distributed jet rotor model 3: Control the distributed jet rotor model 3 to perform dynamic balance adjustment at the working speed until the dynamic balance requirements are met.

[0048] Specifically, after the distributed jet rotor 3 model is installed, the collective pitch, longitudinal periodic pitch, and lateral periodic pitch of the distributed jet rotor 3 are controlled to be 0°. The dynamic balance value of the distributed jet rotor 3 at the working speed is ensured to be less than 0.2IPS by adding or removing the counterweight of the hub arm.

[0049] S4. Adjust the common conicity of the distributed jet rotor 3 model. Control the common conicity of the distributed jet rotor 3 model at the working speed until the common conicity requirement is met.

[0050] Specifically, after the distributed jet rotor 3 model is installed, the collective pitch, longitudinal periodic pitch, and lateral periodic pitch of the distributed jet rotor 3 are controlled to be 0°. The height difference between each blade of the distributed jet rotor 3 is less than half the blade thickness at the working speed by finely adjusting the length of the pitch control rod.

[0051] S5. Conduct distributed jet active flow control hovering wind tunnel tests on the rotor test bench 2 and distributed jet rotor 3 models that meet the requirements in the test wind tunnel 1 and collect test data. Process the test data and analyze the aerodynamic performance of the distributed jet rotor 3 under active jet flow control conditions in the hovering working state.

[0052] After completing the preparation work of S1, S2, S3 and S4, the rotor test bench 2 is in normal condition.

[0053] S52. Keep the main shaft tilt angle of rotor test bench 2 at 0° and collect the zero reading as the initial reading;

[0054] S53. Start the distributed jet rotor 3 at its operating speed. After the distributed jet rotor 3 speed stabilizes, gradually increase the collective pitch of the distributed jet rotor 3 until a decrease in the thrust or thrust coefficient of the distributed jet rotor 3 is observed. Perform active flow control of the distributed jet at each collective pitch state, and collect test data with and without jet control. The test data is collected using an azimuth-synchronized external trigger method, collecting raw data for 80 revolutions, with 64 points collected per revolution. During this period, monitor the balance tension, pitch moment, roll moment, torque, and vibration parameters in real time, ensuring that they are less than the balance design load. The test can only continue if the monitored vibration value is less than 0.2g.

[0055] S54. After data acquisition is completed, manipulate the collective pitch of the distributed jet rotor 3 to 2° and stop the rotor test bench 2.

[0056] S55. Process the experimental data collected in S53. Average the 80 original revolutions of data into 8 revolutions and save them. Perform FFT transformation and calculation on the averaged data to obtain the 0th to 8th order harmonic components of the rotation frequency of the distributed jet rotor 3. The 0th order component is the time average value every 10 revolutions, and the 1st to 8th order harmonic components are the Fourier decomposition values ​​of the time domain signal. Analyze the aerodynamic performance of the distributed jet rotor 3 under hovering conditions with and without active jet flow control. The main analysis focuses on the variation law of the thrust or thrust coefficient of the distributed jet rotor 3 with the collective pitch under conditions with and without active jet flow control. The formula for calculating the thrust coefficient of the distributed jet rotor 3 is:

[0057]

[0058] Where T is the rotor thrust. air density, R is the rotor speed, and R is the rotor radius.

[0059] S6. Conduct a forward flight wind tunnel test of the rotor test bench 2 and the distributed jet rotor 3 model that meet the requirements in the test wind tunnel 1, collect test data, process the test data, and analyze the aerodynamic performance of the distributed jet rotor 3 under forward flight working conditions with and without jet active flow control.

[0060] After completing the preparation work of S1, S2, S3 and S4 on the rotor test bench 2, all systems are in normal condition.

[0061] S62. Collect the initial readings of each main shaft tilt angle of the rotor test bench 2 to deduct the influence of the self-weight of the part above the balance.

[0062] S63, control the distributed jet rotor 3 with a collective pitch of 2°, and start the rotor speed to the operating speed;

[0063] S64. Start the test wind tunnel 1 to the required wind speed. During the wind speed adjustment process, the rotor control system and main shaft tilt system need to be controlled in real time to conduct the forward flight trim test of the distributed jet rotor 3. The forward flight trim test is carried out by gradually increasing the collective pitch of the distributed jet rotor 3 to make the thrust coefficient of the distributed jet rotor 3 trim to the test value. The pitch moment and roll moment of the distributed jet rotor 3 are made to 0 (or kept at a small value) by adjusting the longitudinal and lateral periodic pitch. After the state is stable, the test data under non-controlled conditions are collected. The test data is collected by azimuth angle synchronous external triggering. 80 revolutions of raw data are collected, and 64 points are collected for each revolution.

[0064] S65. Activate jet active flow control. After the state stabilizes, collect test data under control conditions. The test data is collected using the azimuth angle synchronous external triggering method. Collect raw data for 80 revolutions, with 64 points collected per revolution.

[0065] S66. Adjust the test wind speed and repeat steps S64 to S65 until all test wind speed states are completed.

[0066] S67. Adjust the tension coefficient and repeat steps S63 to S66 until all tension coefficient states are completed.

[0067] S68. The wind tunnel 1 is shut down, and the rotor control system is controlled to keep the thrust, pitch moment and roll moment of the distributed jet rotor 3 within the safety threshold. In this embodiment, the safety threshold is 20 Nm. When the wind speed is less than 10 m / s, the total pitch of the distributed jet rotor 3 is reduced to 2°, the longitudinal periodic pitch and the lateral periodic pitch are reduced to 0°, the main shaft tilt system is controlled to return to zero, and the rotor test bench 2 is shut down.

[0068] S69. Process the test data collected from S64 to S67. Average the 80 original revolutions of data into 8 revolutions and save the averaged data. Perform FFT transformation and calculation on the averaged data to obtain the 0th to 8th harmonic components of the rotation frequency of the distributed jet rotor 3. The 0th harmonic component is the time average value every 10 revolutions, and the 1st to 8th harmonic components are the Fourier decomposition values ​​of the time-domain signal. Analyze the aerodynamic performance of the distributed jet rotor 3 under forward flight conditions with and without jet active flow control. The main analysis focuses on the variation of the lift-to-drag ratio of the distributed jet rotor 3 with and without jet active flow control. The formula for calculating the equivalent lift-to-drag ratio of the distributed jet rotor 3 in the forward flight test is:

[0069]

[0070] in, The thrust coefficient of the lower rotor in the wind shaft system. The rotor power coefficient, For the forward ratio, The drag coefficient of the lower rotor of the wind shaft system. This is the rotor hub drag coefficient.

[0071] The formula for calculating the forward ratio is:

[0072]

[0073] Where V is the wind tunnel wind speed. Principal axis tilt angle, R is the rotor speed, and R is the rotor radius.

Claims

1. A rotor wind tunnel testing method based on distributed jet active flow control, characterized in that, Includes the following steps: S1. Rotor test bench (2) dynamic characteristics test, obtain the modal frequencies of each order at the center of the rotor hub of rotor test bench (2); S2, Rotor control matrix calibration, construct the conversion relationship between the blade angle of the distributed jet rotor (3) and the rotor control actuator, and realize the real-time control of the blade pitch angle during blade rotation; S3. Dynamic balance adjustment of the distributed jet rotor (3) model: control the distributed jet rotor (3) model to perform dynamic balance adjustment at the working speed until the dynamic balance requirements are met. S4. Adjust the common conicity of the distributed jet rotor (3) model. Control the common conicity of the distributed jet rotor (3) model at the working speed until the common conicity requirement is met. S5. For the rotor test bench (2) and distributed jet rotor (3) models that meet the requirements, conduct distributed jet active flow control hovering wind tunnel tests in the test wind tunnel (1) and collect test data. Process the test data and analyze the aerodynamic performance of the distributed jet rotor (3) under active jet flow control conditions in the hovering working state. S6. For the rotor test bench (2) and distributed jet rotor (3) model that meet the requirements, conduct a forward flight wind tunnel test of distributed jet active flow control in the test wind tunnel (1) and collect test data. Process the test data and analyze the aerodynamic performance of the distributed jet rotor (3) under forward flight working conditions with and without jet active flow control.

2. The rotor wind tunnel testing method based on distributed jet active flow control according to claim 1, characterized in that, In step S1, the vibration testing equipment is used to identify the longitudinal and transverse modal frequencies of the rotor test bench (2) at the center of the rotor hub. By adjusting the stiffness device of the rotor test bench (2), it is ensured that the rotor test bench (2) does not resonate at the working speed of the distributed jet rotor (3).

3. The rotor wind tunnel testing method based on distributed jet active flow control according to claim 2, characterized in that, In step S2, the blade pitch angle of the distributed jet rotor (3) is a function of the total pitch, the periodic pitch and the blade azimuth angle. By establishing the conversion relationship between the blade pitch angle and the rotor control actuator displacement, the control matrix is ​​constructed to realize the closed-loop control of the blade pitch angle of the distributed jet rotor (3).

4. The rotor wind tunnel testing method based on distributed jet active flow control according to claim 3, characterized in that, The construction of the control matrix in step S2 specifically includes: moving the rotor control actuator to the target position, measuring the blade pitch angle at different azimuth angles using an angle sensor, and constructing a rotor control matrix based on multiple sets of rotor control actuator displacement and corresponding blade pitch angle data.

5. The rotor wind tunnel testing method based on distributed jet active flow control according to claim 4, characterized in that, The dynamic balance adjustment mentioned in step S3 is as follows: After the distributed jet rotor (3) model is installed, the total pitch, longitudinal periodic pitch and lateral periodic pitch of the distributed jet rotor (3) are controlled to be 0°. The dynamic balance value of the distributed jet rotor (3) at the working speed is ensured to be less than 0.2IPS by increasing or decreasing the counterweight of the rotor hub arm.

6. The rotor wind tunnel testing method based on distributed jet active flow control according to claim 5, characterized in that, The common cone adjustment mentioned in step S4 is as follows: After the distributed jet rotor (3) model is installed, control the total pitch, longitudinal periodic pitch and lateral periodic pitch of the distributed jet rotor (3) to 0°, and ensure that the height difference between each blade of the distributed jet rotor (3) is less than half the blade thickness at the working speed by finely adjusting the length of the pitch tie rod.

7. The rotor wind tunnel testing method based on distributed jet active flow control according to claim 6, characterized in that, In step S5, the distributed jet active flow control hovering wind tunnel test includes the following steps: S51, Rotor test bench (2) After completing the preparatory work of steps S1, S2, S3 and S4, confirm that the status of each system is normal; S52. Keep the main shaft tilt angle of the rotor test bench (2) at 0° and collect the zero reading as the initial reading; S53. After starting the distributed jet rotor (3) to the working speed and stabilizing, increase the collective pitch of the distributed jet rotor (3) in steps until the tension or tension coefficient of the distributed jet rotor (3) is observed to decrease. Perform distributed jet active flow control under each collective pitch state, and collect test data with and without jet control respectively. During this period, monitor the balance and vibration parameters in real time to ensure that the parameters are less than the safety threshold. S54. After data acquisition, control the rotor collective pitch to 2° and stop the rotor test bench (2). S55. Process the test data collected in step S53 and analyze the aerodynamic performance of the distributed jet rotor (3) under hovering working state with or without active jet flow control.

8. The rotor wind tunnel testing method based on distributed jet active flow control according to claim 7, characterized in that, In step S53, the test data is collected by azimuth angle synchronous external triggering, and the raw data of the distributed jet rotor (3) with a preset number of revolutions are collected. A preset number of sampling points are collected for each revolution. The data processing in step S55 includes multi-revolution averaging and frequency domain transformation of the raw data. The aerodynamic performance analysis includes the variation law of the thrust or thrust coefficient of the distributed jet rotor (3) with or without jet control as a function of the total pitch.

9. The rotor wind tunnel testing method based on distributed jet active flow control according to claim 8, characterized in that, In step S6, the distributed jet active flow control pre-flight wind tunnel test includes the following steps: S61, Rotor test bench (2) After completing the preparation work of S1, S2, S3 and S4, confirm that the status of each system is normal; S62. Collect the initial readings of each main shaft tilt angle of the rotor test bench (2), and deduct the influence of the self-weight of the part above the balance. S63. Adjust the collective pitch of the distributed jet rotor (3) to 2° and start the distributed jet rotor (3) to the working speed; S64. Start the test wind tunnel (1) to the required wind speed. During the wind speed adjustment process, control the rotor control system and the main shaft tilting system in real time to complete the forward flight trim of the distributed jet rotor (3) and trim the thrust coefficient of the distributed jet rotor (3) to the test value. After the state stabilizes, collect test data under non-control conditions. S65. Activate the active flow control of the jet and collect test data under control conditions after the state stabilizes. S66. Adjust the test wind speed of the test wind tunnel (1), and repeat steps S64 to S65 until all test wind speed states are completed. S67. Adjust the tension coefficient and repeat steps S63 to S66 until all tension coefficient states are completed. S68. Control the test wind tunnel (1) to stop, and at the same time control the rotor control system to keep the rotor thrust, pitching moment and rolling moment within a safe range. When the wind speed is lower than the preset safe wind speed threshold, adjust the rotor collective pitch, periodic pitch and main shaft tilt angle to a safe zero state, and then control the rotor test bench (2) to stop. S69. Process the test data collected in S64~S67 and analyze the aerodynamic performance of the distributed jet rotor (3) under active jet flow control conditions in forward flight working state.

10. The rotor wind tunnel testing method based on distributed jet active flow control according to claim 9, characterized in that, In step S64, the forward flight trim is performed by manipulating the collective pitch of the distributed jet rotor (3) to adjust the thrust coefficient to the test value, and by adjusting the longitudinal and lateral periodic pitch, the pitch moment and roll moment of the distributed jet rotor (3) are brought to zero or kept at a preset small value; in steps S64 and S65, the test data is collected by azimuth angle synchronous external triggering, and the raw data of the distributed jet rotor (3) for a preset number of revolutions are collected, and a preset number of sampling points are collected for each revolution; in step S68, during the shutdown of the test wind tunnel (1), the pitch moment and roll moment of the distributed jet rotor (3) are controlled to remain within the safe threshold; the data processing in step S69 includes multi-revolution averaging and frequency domain transformation of the raw data, and the aerodynamic performance analysis includes the variation law of the lift-to-drag ratio of the distributed jet rotor (3) with or without jet control as a function of the forward ratio.

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