A wind tunnel test method for spiral flutter using a motor to control rotor speed

Abstract

The present invention belongs to the technical field of wind tunnel testing and discloses a spiral flutter wind tunnel test method using a motor to control rotor speed. The steps are as follows: constructing a spiral flutter wind tunnel test device with a motor to control the speed; a comprehensive control method for the motor speed and the wind tunnel inflow velocity; and formally conducting a spiral flutter wind tunnel test, thereby providing a spiral flutter wind tunnel test method using a motor to control the rotor speed. The wind tunnel test speed regulation method provided by the present invention can ensure comprehensive control of the speed and inflow velocity while allowing the motor to operate within a safe load range, thereby ensuring the safety and success of the test. The proposed spiral flutter wind tunnel test method using a motor to control the rotor speed provides technical support for spiral flutter wind tunnel tests of tiltrotors and fixed-wing propeller aircraft.

Description

Technical Field

[0001] The invention belongs to the technical field of wind tunnel testing and relates to a spiral flutter wind tunnel testing method for controlling the rotation speed of a rotor by using a motor. Background Art

[0002] Spiral flutter is a common aeroelastic divergence phenomenon encountered in propeller-powered fixed-wing propeller aircraft, tiltrotors, and other aircraft. It occurs when the rotor engine nacelle and propeller system, supported by a flexible wing, undergo specific rotational speed and airflow velocity conditions. Currently, spiral flutter is difficult to accurately predict through theoretical modeling and simulation analysis. Wind tunnel testing is a key technical approach to studying spiral flutter. Unlike traditional fixed-wing aircraft flutter wind tunnel testing, spiral flutter is influenced by a combination of airflow velocity and rotational speed. Therefore, spiral flutter wind tunnel testing requires comprehensive control of both speed and airflow velocity to achieve the desired spiral flutter state. Unpowered "windmill mode" propeller speed can be adjusted by varying the rotor pitch angle, matching the speed to the airflow velocity. Active speed adjustment is not possible, limiting the range of parameter variations in wind tunnel testing. Powered spiral flutter testing devices can actively adjust the rotor rotational speed, expanding the testing range and enabling a better understanding of the influence of spiral flutter.

[0003] The spiral flutter of the rotor system is the result of the combined influence of the incoming flow velocity and the rotor speed. Currently, there is no wind tunnel test method for spiral flutter in which the rotor speed is controlled by a motor, and there is no comprehensive control method for the motor speed and the wind tunnel incoming flow velocity. Summary of the Invention

[0004] Apart from the wind tunnel test model device, the difference between spiral flutter and fixed-wing flutter is that spiral flutter is the result of the combined influence of the rotor speed and the air inlet velocity. The spiral flutter wind tunnel test requires comprehensive adjustment of the speed and the inlet velocity. The present invention provides a spiral flutter wind tunnel test method that uses a motor to control the rotor speed. The motor actively increases the rotor speed and matches the gradually increasing wind tunnel inlet velocity to achieve a spiral flutter state, thereby achieving the reproduction of the spiral flutter phenomenon in the wind tunnel and conducting regularity research. At the same time, in order to adapt to the rated power of the speed-regulating motor, a joint debugging method of the motor speed and the wind tunnel inlet velocity is provided. By adjusting the wind tunnel inlet velocity, the inlet wind velocity that drives the motor and rotor to rotate is changed, and the rotational power output by the active rotation of the motor is coordinated to achieve the target forward ratio. , and ensure that the motor operates within the rated power range to avoid the danger of overload operation.

[0005] The technical solution of the present invention:

[0006] A spiral flutter wind tunnel test method for controlling rotor speed using a motor comprises the following steps:

[0007] Step 1: constructing a motor-controlled speed spiral flutter wind tunnel test device 12;

[0008] The motor-controlled speed spiral flutter wind tunnel test device 12 includes a wing 1, a nacelle 2, a rotor 3, a motor water cooling cabinet 11 and a motor control cabinet 10; a motor 4, a coupling 5, a bearing 6 and a propeller hub 7 are installed in the nacelle 2; the motor control cabinet 10 controls the speed of the rotor of the motor 4 and the rotor 3 through the motor control line 8; the water cooling cabinet 11 cools the motor 4 through the water cooling connection line 9; one end of the rotor shaft 15 is directly connected to the output shaft of the motor 4 through the coupling 5, and the rotor shaft 15 is fixedly supported by two bearings 6; the rotor shaft The other end of 15 is connected to the hub 7, which together with the blades constitutes the rotor 3; the motor 4 is placed in the nacelle 2, which is connected to the wing 1; the motor-controlled speed spiral flutter wind tunnel test device 12 is installed on the side wall of the wind tunnel closed test section 13; the motor control line 8 and the water cooling connection line 9 pass through the wing 1, out of the side wall of the wind tunnel closed test section 13, and are respectively connected to the motor control cabinet 10 and the motor water cooling cabinet 11; after the motor-controlled speed spiral flutter wind tunnel test device 12 is installed, a spiral flutter wind tunnel test is performed in the wind tunnel 14;

[0009] Step 2: Comprehensive control method of motor speed and wind tunnel inflow velocity;

[0010] During the spiral flutter wind tunnel test, both the motor speed and the wind tunnel inflow velocity need to be within a certain range. The wind tunnel inflow velocity is achieved by adjusting the fan power of the wind tunnel. The motor speed is achieved by the combined effect of motor 4 and the wind tunnel inflow velocity.

[0011] According to the output power of the motor 4 and the power of the wind tunnel flow velocity to drive the motor 4 to rotate, the working modes of the motor 4 are divided into the following three modes:

[0012] 1) Windmill mode: Driven by the wind tunnel flow velocity, rotor 3 and motor 4 rotate at a constant speed, overcoming the damping, and the output power of motor 4 is zero;

[0013] 2) Output mode: Motor 4 actively drives rotor 3 to rotate, rotor 3 is in active acceleration state, the output power of motor 4 is positive, the current displayed in motor 4 increases, and the water temperature of motor water cooler 11 increases;

[0014] 3) Input mode: Driven by the wind tunnel flow velocity, the motor 4 is in a passive acceleration state. The output power of the motor 4 is positive, the current displayed in the motor 4 decreases, and the water temperature of the motor water cooling cabinet 11 decreases.

[0015] To ensure safety, the motor 4 cannot work in the input mode and output mode for a long time; according to the motor speed of the motor 4 entering the windmill mode , to determine the pitch angle and wind tunnel flow velocity; in the windmill mode, the motor 4 is switched between the input mode and the output mode by increasing the motor speed and the wind tunnel flow velocity, reaching the next load-balanced windmill mode state point, and finally reaching the spiral flutter boundary;

[0016] Step 21, designing a motor windmill mode state table; in order to keep the motor 4 in a state close to the windmill mode during the spiral flutter wind tunnel test, designing a motor windmill mode state table; the motor windmill mode state table is when the motor control speed spiral flutter wind tunnel test device 12 and the pitch angle A are determined, when the wind tunnel inflow velocity is V, the wind tunnel inflow drives the motor 4 to rotate to a stable speed , and the table consisting of the state where the motor 4 is in windmill mode;

[0017] Table 1 Motor windmill mode status table

[0018]

[0019] Step 22, in order to realize the windmill mode of the motor 4, a joint debugging method of the motor speed and the wind tunnel flow velocity is designed; after the motor speed control spiral flutter wind tunnel test device 12 is installed in the wind tunnel, the pitch angle is set. , so that the motor 4 is in a no-load state, and the motor control cabinet 10 reads the actual speed of the motor 4 measured by the speed sensor inside the motor 4;

[0020] Step 23: To find the load balance state of motor 4, start the wind tunnel and gradually increase the wind tunnel flow speed. The wind tunnel flow speed drives the rotor 3 to accelerate the rotation. Motor 4 enters the input mode and the motor control cabinet 10 shows that the motor speed increases. Gradually increase the wind tunnel flow speed until the wind tunnel flow speed reaches the state point shown in the motor windmill mode state table. , observe the motor speed displayed on the motor control cabinet 10. When the motor speed reaches a stable state, read the motor speed displayed on the motor control cabinet 10 and record it in the motor windmill mode state table. At the position, a state point measurement is completed;

[0021] Step 24: After completing the state point measurement, gradually increase the wind tunnel flow velocity to reach the next wind tunnel flow velocity , and continue to observe the motor speed displayed by the motor control cabinet 10. When the displayed motor speed reaches a stable state, record it as the motor windmill mode state table. State point; and so on, continue to change the wind tunnel flow speed to complete the motor windmill mode state table pitch angle The corresponding motor speed is measured to match the wind tunnel inflow velocity. At this point, one train measurement is completed; the pitch angle is adjusted to enter the next train test.

[0022] Step 25: After completing the current train measurement test, the wind tunnel is stopped and the pitch angle is adjusted to , continue with steps 23-24 to complete the measurement of the load-balanced motor speed corresponding to all pitch angles and wind tunnel inflow velocities in the motor windmill mode state table. At this time, the joint debugging test of the motor speed and wind tunnel inflow velocity is completed;

[0023] Step 3: Officially enter the spiral flutter wind tunnel test and provide a spiral flutter wind tunnel test method in which the rotor speed is controlled by a motor;

[0024] When the motor controls the speed of the spiral flutter wind tunnel test device 12 to a given value, the spiral flutter boundary is composed of the forward ratio of the wind tunnel flow velocity and the motor speed. It is determined that the spiral flutter wind tunnel test requires changing the motor speed Ω and the wind tunnel inflow velocity V simultaneously; under zero wind speed, start motor 4 and gradually increase the motor speed. Motor 4 is in output mode. After the motor speed is close to stable, turn on the wind tunnel, set the target wind tunnel inflow velocity, and rotate rotor 3 at the wind tunnel inflow velocity. Motor 4 enters input mode. When the wind tunnel inflow velocity and motor speed reach the load balance state in the motor windmill mode state table in step 2, motor 4 enters windmill mode and can operate for a long time.

[0025] Step 31: To reach the spiral flutter boundary, the motor speed is continuously increased, and the motor 4 enters the output mode. After the motor speed is nearly stable, the wind tunnel flow velocity is continuously increased, and the motor 4 enters the input mode. This is until the load is balanced and the next windmill mode state point is reached.

[0026] Step 32: Repeat step 31, and according to the load balance state of the motor windmill mode state table, sequentially increase the motor speed and the wind tunnel inlet flow velocity until the combination of the motor speed and the wind tunnel inlet flow velocity approaches the spiral flutter boundary, at which point the joint adjustment of the motor speed and the wind tunnel inlet flow velocity is stopped;

[0027] Step 33: When the spiral flutter boundary is reached, only the motor wind speed is increased, and the motion state of the spiral flutter wind tunnel test device 12 controlled by the motor is observed. When the spiral flutter wind tunnel test device 12 controlled by the motor reaches a vortex state, it is considered that a point on the spiral flutter boundary has been found.

[0028] Step 34: Repeat steps 31 to 33 to continue the wind tunnel test and find other points on the spiral flutter boundary. Once all points on the spiral flutter boundary are measured, the test is considered complete.

[0029] In step 35, the wind tunnel is shut down, and the pitch angle or other test device design elements that may potentially affect the spiral flutter boundary are adjusted. The next test state is entered, and steps 31 to 34 are repeated to complete the next loaded spiral flutter boundary measurement wind tunnel test until all test state measurements are completed and the test ends.

[0030] Beneficial effects of the present invention: The present invention controls the rotor speed through a motor to achieve comprehensive control of the speed and the wind tunnel inflow velocity, ensuring that a wide range of wind speed adjustments can be performed at the same speed during the test, and achieving the matching requirements of the spiral flutter speed and wind speed. At the same time, a joint debugging method for the motor speed and the wind tunnel inflow velocity is provided. Through preliminary tests, a load balance state in which the speed and the inflow velocity match each other is obtained. The wind tunnel test speed regulation method provided can ensure comprehensive control of the speed and the inflow velocity while making the motor work within the load safety range, ensuring the safety and success of the test. The proposed motor-controlled rotor speed spiral flutter wind tunnel test method provides technical support for spiral flutter wind tunnel tests of tilt-rotor aircraft and fixed-wing propeller aircraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the wind tunnel test model.

[0032] Figure 2 This is a schematic diagram of motor speed control in wind tunnel testing.

[0033] Figure 3 This is a schematic diagram of speed regulation in spiral flutter wind tunnel test.

[0034] Figure 4 This is a diagram of the actual speed adjustment process in the spiral flutter wind tunnel test.

[0035] In the figure: 1 wing, 2 nacelle, 3 rotor, 4 motor, 5 coupling, 6 bearing, 7 hub, 8 motor control line, 9 motor water cooling line, 10 motor control cabinet, 11 motor water cooling cabinet, 12 wind tunnel test model, 13 wind tunnel closed test section, 14 wind tunnel, 15 rotor shaft. DETAILED DESCRIPTION

[0036] The specific implementation of the present invention is further described below in conjunction with the accompanying drawings and technical solutions.

[0037] A wind tunnel test method for spiral flutter with motor-controlled rotor speed. Figure 1-3 As shown in FIG, the spiral flutter wind tunnel test method based on controlling the rotor speed with an electric motor includes the following steps:

[0038] Step 1, a motor controls the speed of a spiral flutter wind tunnel test device 12;

[0039] The motor-controlled speed spiral flutter wind tunnel test device 12 includes a wing 1, a nacelle 2, a rotor 3, a motor water cooling cabinet 11 and a motor control cabinet 10; a motor 4, a coupling 5, a bearing 6 and a propeller hub 7 are installed in the nacelle 2; the motor control cabinet 10 controls the speed of the rotor of the motor 4 and the rotor 3 through the motor control line 8; the water cooling cabinet 11 cools the motor 4 through the water cooling connection line 9; one end of the rotor shaft 15 is directly connected to the output shaft of the motor 4 through the coupling 5, and the rotor shaft 15 is fixedly supported by two bearings 6; the rotor shaft The other end of 15 is connected to the hub 7, which together with the blades constitutes the rotor 3; the motor 4 is placed in the nacelle 2, which is connected to the wing 1; the motor-controlled speed spiral flutter wind tunnel test device 12 is installed on the side wall of the wind tunnel closed test section 13; the motor control line 8 and the water cooling connection line 9 pass through the wing 1, out of the side wall of the wind tunnel closed test section 13, and are respectively connected to the motor control cabinet 10 and the motor water cooling cabinet 11; after the motor-controlled speed spiral flutter wind tunnel test device 12 is installed, a spiral flutter wind tunnel test is performed in the wind tunnel 14;

[0040] Step 2: Comprehensive control method for motor speed and wind tunnel inflow velocity. During the spiral flutter wind tunnel test, both the motor speed and the wind tunnel inflow velocity need to be within a certain range. Among them, the wind tunnel inflow velocity is achieved by adjusting the fan power of the wind tunnel. The rotor speed is achieved by the combined action of motor 4 and wind tunnel inflow velocity. According to the output power of motor 4 and the power of wind tunnel inflow velocity to drive motor 4 to rotate, the motor working mode is divided into the following three types:

[0041] 1) Windmill mode: Driven by the wind, rotor 3 and motor 4 rotate at a constant speed, overcoming damping, and motor 4 output power is zero.

[0042] 2) Output mode: Motor 4 actively drives rotor 3 to rotate. Rotor 3 is in an active acceleration state. Motor 4 outputs positive power, the current displayed in motor 4 increases, and the water temperature in water cooler 11 increases.

[0043] 3) Input mode: Driven by the wind tunnel flow velocity, motor 4 is in a passive acceleration state. The output power of motor 4 is positive, the current displayed in motor 4 decreases, and the water temperature in water cooling cabinet 11 decreases.

[0044] To ensure safety, the motor 4 cannot work in the input mode or output mode for a long time. Find the appropriate pitch angle A and wind tunnel flow velocity V to make the motor 4 enter the windmill mode. , i.e. the windmill mode of motor 4. In the windmill mode, by increasing the motor speed and wind tunnel inflow velocity , so that the motor 4 switches between the input mode and the output mode, reaches the next load-balanced windmill mode state point, and finally reaches the spiral flutter boundary.

[0045] Step 21: To achieve the windmill mode with balanced motor load described in Step 2 during the wind tunnel test, a motor load balance state table is designed to identify the matching relationship between the wind tunnel incoming flow velocity V and the motor speed Ω for different total pitch angles A. One state point in Table 1 represents the speed that matches the incoming flow velocity under the total pitch angle. At this point, rotor 3 achieves load balance, motor 4's output power is zero, and windmill mode is entered.

[0046] Step 22, in order to realize the windmill mode of the motor 4, a joint debugging method of the motor speed and the wind tunnel flow velocity is designed; after the motor speed control spiral flutter wind tunnel test device 12 is installed in the wind tunnel, the pitch angle is set. , turn off the speed regulating motor 4, at this time the motor 4 is in a no-load state, and the motor control cabinet 10 reads the actual speed of the motor 4 measured by the speed sensor inside the motor 4;

[0047] Step 23: To find the load balance state of motor 4, start the wind tunnel and set the wind tunnel flow velocity to zero. The wind tunnel flow velocity drives the rotor 3 to accelerate the rotation. Motor 4 enters the input mode and the motor control cabinet 10 displays an increase in the motor speed Ω. Gradually increase the wind tunnel flow velocity V until the wind tunnel flow velocity V reaches the state point shown in the motor windmill mode state table. , observe the motor speed Ω displayed on the motor control cabinet 10. When the motor speed Ω reaches stability, read the motor speed Ω displayed on the motor control cabinet 10 and record it in the motor windmill mode status table. At the position, a state point measurement is completed;

[0048] In step 24, after completing the state point measurement described in step 23, gradually increase the wind tunnel flow velocity V until it reaches the next wind tunnel flow velocity = 20.7 m / s. Continue observing the motor 4 speed displayed on the motor control cabinet 10. When the displayed speed Ω stabilizes, read the motor speed Ω = 360 RPM displayed on the motor control cabinet 10 again and record this as the state point in Table 1. Continue changing the wind tunnel flow velocity V in this manner until the rotor speed Ω corresponding to all wind tunnel flow velocities V corresponding to the pitch angles in Table 1 is measured. At this point, one trip measurement is complete.

[0049] Step 24: After completing the one-vehicle test described in steps 23-24, the wind tunnel is stopped, the total pitch angle is adjusted to A2 = 35°, and the process described in steps 23-24 is continued to complete the measurement of the load-balanced rotor speed Ω corresponding to all pitch angles A and incoming flow velocities V in Table 1. At this time, the joint debugging test of the speed and incoming flow velocity is completed, and the actual motor load balance state table shown in Table 2, that is, the actual motor windmill mode state table, is obtained.

[0050] Table 2 Motor windmill mode status table (actual test values)

[0051]

[0052] Step 3, formally enter the spiral flutter wind tunnel test, providing a spiral flutter wind tunnel test method with motor-controlled rotor speed. When the motor-controlled speed spiral flutter wind tunnel test device 12 is given, the spiral flutter boundary is determined by the forward ratio composed of the wind tunnel inflow velocity V and the rotor speed Ω. The formal wind tunnel test requires changing the rotor speed Ω and the inflow velocity V at the same time. Figure 3 As shown, speed control method L directly sets the target speed. This puts the motor in a high-load output state, making it difficult to achieve the target speed due to power limitations. Furthermore, high-load operation can damage the motor. Speed ​​control method M directly sets the target wind speed. Driven by the rotor, the motor is in a high-load input state, which can easily overheat and burn out. To address these issues, speed control method N is provided.

[0053] Step 31 implements the speed control mode N described in step 3. Given an initial pitch angle A = 50° and zero wind speed, motor 4 is turned on and a low target speed Ω = 50 RPM is set. The motor is in output mode. After the speed stabilizes, the wind tunnel is turned on and a target wind speed V = 5 m / s is set. The wind tunnel airflow drives the rotor, and the motor enters input mode. When the airflow speed and speed reach the actual motor load balance state obtained in Table 2 in step 2, the motor enters windmill mode, allowing for extended operation.

[0054] Step 32, in order to achieve the Figure 3 The flutter boundary in Figure 4 As shown, the motor speed is continued to increase to 141RPM, allowing the motor to enter the output mode again. After the speed is close to stable, the wind tunnel wind speed is continued to increase to 17.1m / s, allowing the motor to enter the input mode again until the load is balanced and the next windmill mode state point is reached.

[0055] Step 33, in order to achieve the Figure 3 The flutter boundary in Figure 4 As shown, continue to increase the motor speed to 200RPM, let the motor enter the output mode again, and after the speed is close to stable, continue to increase the wind tunnel wind speed to 24.3m / s, let the motor enter the input mode again, until the load is balanced and reaches the next windmill mode state point.

[0056] Step 34: Using the adjustment method in steps 32 and 33, according to the actual load balance state of the motor obtained in Table 2, the motor speed Ω and the wind tunnel flow velocity V are increased sequentially until the speed Ω and the flow velocity V are close to Figure 4The flutter boundary shown is where the joint adjustment of the rotational speed Ω and the incoming flow velocity V is stopped.

[0057] In step 35, near the flutter boundary reached in step 34, the motor speed Ω = 280 RPM. At this time, only the wind speed V is increased, and the motion state of the spiral flutter wind tunnel test apparatus is observed. When the wind speed V = 34 m / s, the rotor system reaches a vortex state, which is considered to be the point I on the spiral flutter boundary.

[0058] Step 36, repeat 31 to 35, continue the wind tunnel test, and find Figure 3 For other points on the flutter boundary shown, once all points on the flutter boundary are measured, a train test is considered completed.

[0059] Step 37: Stop the wind tunnel, adjust the pitch angle A, or other test device design factors that may affect the spiral flutter boundary, enter the next test state, repeat steps 31 to 36, and complete the next loaded spiral flutter boundary measurement wind tunnel test until all test state measurements are completed and the test ends. Figure 4 shown.

Claims

1. A spiral flutter wind tunnel test method using a motor to control the rotor speed, characterized in that: The following steps are involved: Step 1: Construct a motor-controlled speed spiral flutter wind tunnel test device (12); Step 2: Comprehensive control method of motor speed and wind tunnel inflow velocity; During the spiral flutter wind tunnel test, the motor speed and the wind tunnel inflow velocity need to reach a certain range; the wind tunnel inflow velocity is achieved by adjusting the wind tunnel fan power; the motor speed is achieved by the combined action of the motor (4) drive and the wind tunnel inflow velocity; According to the output power of the motor (4) and the power of the wind tunnel flow velocity to drive the motor (4) to rotate, the working modes of the motor (4) are divided into the following three types: 1) Windmill mode: The rotor (3) and the motor (4) rotate at a constant speed under the influence of the wind tunnel flow velocity, overcoming the damping, and the output power of the motor (4) is zero; 2) Output mode: the motor (4) actively drives the rotor (3) to rotate, the rotor (3) is in an active acceleration state, the output power of the motor (4) is positive, the current displayed in the motor (4) increases, and the water temperature of the motor water cooling cabinet (11) increases; 3) Input mode: The motor (4) is in a passive acceleration state under the influence of the wind tunnel flow velocity, the output power of the motor (4) is positive, the current displayed in the motor (4) decreases, and the water temperature of the motor water cooling cabinet (11) decreases; In order to ensure safety, the motor (4) cannot work in the input mode and the output mode for a long time; according to the motor speed of the motor (4) entering the windmill mode , to determine the pitch angle and the wind tunnel flow velocity; in the windmill mode, the motor (4) switches between the input mode and the output mode by increasing the motor speed and the wind tunnel flow velocity, reaches the next load-balanced windmill mode state point, and finally reaches the spiral flutter boundary; Step 3: Officially enter the spiral flutter wind tunnel test and provide a spiral flutter wind tunnel test method in which the rotor speed is controlled by a motor; When the motor-controlled speed spiral flutter wind tunnel test device (12) is given, the spiral flutter boundary is composed of the forward ratio of the wind tunnel flow velocity and the motor speed. It is determined that the spiral flutter wind tunnel test requires changing the motor speed Ω and the wind tunnel inflow speed V at the same time; under zero wind speed, the motor (4) is turned on and the motor speed is gradually increased. The motor (4) is in output mode. After the motor speed is close to stable, the wind tunnel is turned on and the target wind tunnel inflow speed is set. The wind tunnel inflow speed rotor (3) is rotated and the motor (4) enters the input mode. When the wind tunnel inflow speed and the motor speed reach the load balance state in the motor windmill mode state table in step 2, the motor (4) enters the windmill mode and can operate for a long time.

2. The spiral flutter wind tunnel test method for controlling the rotor speed using a motor according to claim 1, characterized in that: The motor-controlled speed spiral flutter wind tunnel test device (12) comprises a wing (1), a nacelle (2), a rotor (3), a motor water cooling cabinet (11) and a motor control cabinet (10); a motor (4), a coupling (5), a bearing (6) and a propeller hub (7) are installed in the nacelle (2); the motor control cabinet (10) controls the speed of the rotor of the motor (4) and the rotor (3) through the motor control line (8); the water cooling cabinet (11) cools the motor (4) through the water cooling connection line (9); one end of the rotor shaft (15) is directly connected to the output shaft of the motor (4) through the coupling (5), and the rotor shaft (15) is fixedly supported by two bearings (6). The other end of the rotor shaft (15) is connected to the propeller hub (7), and the propeller hub (7) and the propeller blades together constitute the rotor (3); the motor (4) is placed in the nacelle (2), and the nacelle (2) is connected to the wing (1); the motor-controlled speed spiral flutter wind tunnel test device (12) is installed on the side wall of the wind tunnel closed test section (13); the motor control line (8) and the water cooling connection line (9) pass through the wing (1), pass through the side wall of the wind tunnel closed test section (13), and are correspondingly connected to the motor control cabinet (10) and the motor water cooling cabinet (11); after the motor-controlled speed spiral flutter wind tunnel test device (12) is installed, a spiral flutter wind tunnel test is carried out in the wind tunnel (14).

3. The spiral flutter wind tunnel test method for controlling the rotor speed using a motor according to claim 1, characterized in that: The specific implementation process of step 2 is as follows: Step 21, designing a motor windmill mode state table; in order to keep the motor (4) in a state close to the windmill mode during the spiral flutter wind tunnel test, designing a motor windmill mode state table; the motor windmill mode state table is when the motor control speed spiral flutter wind tunnel test device (12) and the pitch angle A are determined, when the wind tunnel inflow velocity is V, the wind tunnel inflow drives the motor (4) to rotate to reach a stable speed , and the motor (4) is in the windmill mode; Step 22, in order to realize the windmill mode of the motor (4), a joint debugging method of the motor speed and the wind tunnel flow velocity is designed; after the motor speed control spiral flutter wind tunnel test device (12) is installed in the wind tunnel, the pitch angle is set. , the motor (4) is placed in a no-load state, and the motor control cabinet (10) reads the actual speed of the motor (4) measured by the speed sensor inside the motor (4); Step 23, in order to find the load balance state of the motor (4), the wind tunnel is turned on and the wind tunnel flow speed is gradually increased. The wind tunnel flow speed drives the rotor (3) to accelerate the rotation, and the motor (4) enters the input mode. The motor control cabinet (10) displays that the motor speed increases; the wind tunnel flow speed is gradually increased until the wind tunnel flow speed reaches the state point shown in the motor windmill mode state table. , observe the motor speed displayed on the motor control cabinet (10). When the motor speed reaches a stable state, read the motor speed displayed on the motor control cabinet (10) and record it in the motor windmill mode status table. At the position, a state point measurement is completed; Step 24: After completing the state point measurement, gradually increase the wind tunnel flow velocity to reach the next wind tunnel flow velocity , and continue to observe the motor speed displayed on the motor control cabinet (10). When the displayed motor speed reaches a stable state, record it as the motor windmill mode state table. State point; and so on, continue to change the wind tunnel flow speed to complete the motor windmill mode state table pitch angle The corresponding motor speed is measured to match the wind tunnel inflow velocity. At this point, one train measurement is completed; the pitch angle is adjusted to enter the next train test. Step 25: After completing the current train measurement test, the wind tunnel is stopped and the pitch angle is adjusted to , continue with steps 23-24 to complete the measurement of the load-balanced motor speed corresponding to all pitch angles and wind tunnel inflow velocities in the motor windmill mode state table. At this time, the joint debugging test of the motor speed and wind tunnel inflow velocity is completed.

4. The spiral flutter wind tunnel test method for controlling the rotor speed using a motor according to claim 1, characterized in that: The specific implementation process of step 3 is as follows: Step 31, in order to reach the spiral flutter boundary, the motor speed is continuously increased, and the motor (4) enters the output mode here. After the motor speed is close to stable, the wind tunnel flow velocity is continuously increased, and the motor (4) enters the input mode here, until the load balance state is reached, and the next windmill mode state point is reached; Step 32: Repeat step 31, and according to the load balance state of the motor windmill mode state table, sequentially increase the motor speed and the wind tunnel inlet flow velocity until the combination of the motor speed and the wind tunnel inlet flow velocity approaches the spiral flutter boundary, at which point the joint adjustment of the motor speed and the wind tunnel inlet flow velocity is stopped; Step 33, when the spiral flutter boundary is reached, only the motor wind speed is increased, and the motion state of the motor-controlled speed spiral flutter wind tunnel test device (12) is observed. When the motor-controlled speed spiral flutter wind tunnel test device (12) reaches a vortex state, it is considered that a point on the spiral flutter boundary is found; Step 34: Repeat steps 31 to 33 to continue the wind tunnel test and find other points on the spiral flutter boundary. Once all points on the spiral flutter boundary are measured, the test is considered complete. In step 35, the wind tunnel is shut down, and the pitch angle or other test device design elements that may potentially affect the spiral flutter boundary are adjusted. The next test state is entered, and steps 31 to 34 are repeated to complete the next loaded spiral flutter boundary measurement wind tunnel test until all test state measurements are completed and the test ends.

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