A device for suppressing vibration inertia of wind tunnel models

Abstract

The present invention relates to the field of active vibration control for aircraft wind tunnel models and proposes a device for suppressing the inertial actuation of wind tunnel model vibrations. The device is capable of suppressing the combined pitch and yaw vibrations of the wind tunnel model. The device comprises a housing base, end caps, bearings, a spindle, a positioning nut, a positioning sleeve, an inertial mass block, a coupling, a motor component, and fasteners including end cap set screws, motor mounting screws, a motor coupling key, a spindle coupling key, and a mass block coupling key. The device is coaxially mounted with a force balance within the tail cavity of the aircraft model. By driving the inertial mass block in circular motion, it provides an inertial vibration suppression force, thereby controlling the combined pitch and yaw vibrations of the aircraft wind tunnel model. The device has a compact structure and is easy to control. Installation within the model cavity avoids any additional impact on the model's aerodynamic shape, and has great potential for application.

Description

Technical Field

[0001] The present invention relates to the field of active vibration control of aircraft wind tunnel models, and in particular to a device for suppressing inertial actuation of wind tunnel model vibration, which has the function of suppressing the combined pitch and yaw vibration of the wind tunnel model. Background Art

[0002] Wind tunnel model testing is an important method for studying aircraft aerodynamic characteristics and reducing development costs and risks. Aircraft models are most commonly mounted in wind tunnels using tail and belly supports. This cantilever-like structure exhibits weak stiffness and low damping. Furthermore, due to the pulsating forces of the airflow in the test section, the model is prone to irregular vibrations, which can seriously affect the accuracy of aerodynamic measurements and even damage the structure itself. Active vibration suppression is essential.

[0003] Currently, active vibration suppression devices based on piezoelectric ceramics have become mainstream. Using piezoelectric ceramics as driving elements, the vibration suppression device is mounted at the end or mid-section of a strut. A control voltage is applied to the device to generate a damping force. These devices are widely used in tail-supported models. However, for large-scale wind tunnel models used in low-speed tests, the belly support method is generally used. The irregular strut structure makes the placement of the vibration suppression device difficult, and the complex vibration modes significantly increase the control complexity.

[0004] Vibration control methods based on the inertial actuation principle have been widely used in fields such as controlling ship vibration caused by operational loads and bridge vibration caused by wind loads, thanks to their simple structure and low control cost. In the field of ship vibration control, electric vibration dampers based on the inertial actuation principle have been commercialized. They work by controlling the centrifugal control force output by a rotating inertial actuator to suppress low-frequency structural vibrations of the ship's main engine and propeller. In the field of bridge vibration control, dual-rotor dampers are used to provide a periodically varying damping force to suppress the periodic vibration of the bridge caused by wind loads.

[0005] However, it has been rarely used in the field of wind tunnel model vibration control. In their 2007 paper, "Experimental Study of an Active Vibration Reduction System for a Transonic Wind Tunnel Force Measurement Model," Chen Weidong and others from Nanjing University of Aeronautics and Astronautics developed an electromagnetic inertial actuator and constructed an active vibration control system. Using the vibration acceleration signal as feedback, the actuator outputs an inertial force in the pitch direction through control decisions, achieving a vibration suppression effect of over 70%. This device utilizes the internal space of the model, installing two electromagnetic inertial actuators in parallel in the front cavity. However, their output force is only in the pitch direction, limiting their ability to suppress vibration in that direction. Furthermore, the device is bulky and has limited output force, limiting its vibration suppression effectiveness. Summary of the Invention

[0006] The present invention primarily addresses the technical challenge of overcoming the shortcomings of existing technologies by inventing a device for suppressing the inertial actuation of wind tunnel model vibrations, achieving combined vibration control of the pitch and yaw degrees of freedom of an aircraft wind tunnel model. The device incorporates an inertial mass block 8 driven by a motor. This mass block utilizes its circular motion to generate an inertial centrifugal force, controlling its output to produce an inertial force opposite to the combined force of the pitch and yaw vibrations, thereby suppressing the combined pitch and yaw vibrations of the model. The device is installed within the tail cavity of the model, coaxially with the tail strut. It features a compact structure, simple control, and does not affect the model's aerodynamic shape.

[0007] The technical solution adopted in the present invention is as follows:

[0008] A wind tunnel model vibration inertia actuation suppression device includes a housing base 1, an end cover 2, an end cover set screw 3, a bearing 4, a main shaft 5, a pre-tightening nut 6, a positioning sleeve 7, an inertial mass block 8, a coupling 9, a motor 10, a motor mounting screw 11 and a mass block connecting key 15, which are assembled and connected to achieve motion and force transmission;

[0009] The outer surface of the top end is connected to the end cover 2 by the end cover fixing screw 3, and the inner surface of the bottom end is connected to the motor 10 by the motor mounting screw 11; a groove is provided on the top of the outer shell base 1 for installing the bearing 4; the lower end of the main shaft 5 is connected to the motor 10 through the coupling 9, and the coupling 9 transmits the output torque of the motor 10 to the main shaft 5 through the motor coupling key 13 and the main shaft coupling key 14, and then drives the inertial mass block 8 to perform a circular motion centered on the main shaft through the mass block coupling key 15, and the centrifugal inertia force generated by it reacts on the outer shell base 1; the upper end of the main shaft 5 passes through the outer shell base 1 and is connected to the bearing 4; the pre-tightening nut 6 and the positioning sleeve 7 are fixed on the main shaft 5 in sequence; the inertial mass block 8 is in a "T" shape and performs a circular motion centered on the main shaft 5. It is axially fixed on the main shaft 5 by the pre-tightening nut 6 and the positioning sleeve 7, and is circumferentially fixed by the mass block coupling key 15;

[0010] Six mounting holes 12 are evenly arranged on the convex part of the bottom edge of the outer shell base 1, which are used to install the entire device in the tail cavity of the aircraft model 16. The force balance 17 is located on the top side of the outer shell base 1. The wind tunnel model vibration inertia actuation suppression device 18 is coaxially installed with the force balance 17 in the tail cavity of the aircraft model 16 to realize the composite vibration control of the pitch and yaw directions of the aircraft wind tunnel model.

[0011] The coupling 9 is connected to the motor via the motor coupling key 13 and is connected to the main shaft via the main shaft coupling key 14 .

[0012] The beneficial effects of the present invention include the design and invention of a wind tunnel model vibration inertial actuation suppression device that effectively and actively suppresses the model's pitch and yaw degrees of freedom vibrations induced by airflow loads. A motor drives an inertial mass block in circular motion, generating a centrifugal inertial force that acts on the model's support rod system. This centrifugal inertial force is controlled to be in real time opposite to the direction of the resultant force of the model's pitch and yaw degrees of freedom vibrations, thereby weakening the model's composite vibrations induced by airflow loads, increasing the damping of the model support system, ensuring model stability, and improving the accuracy of wind tunnel test measurement data. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is an overall structural diagram of a wind tunnel model vibration inertia actuation suppression device according to the present invention;

[0014] Figure 2 is a main cross-sectional view of the device of the present invention;

[0015] Figure 3 Schematic diagram of the vibration suppression principle of the device of the present invention;

[0016] Figure 4 Schematic diagram of the installation of the device of the present invention;

[0017] Figure 5 This is a graph showing the vibration acceleration monitoring results of a hammer impact test on an aircraft model.

[0018] In the figure: 1-housing base, 2-end cover, 3-end cover fastening screw, 4-bearing, 5-spindle, 6-preload nut, 7-positioning sleeve, 8-inertia mass block, 9-coupling, 10-motor, 11-motor mounting screw, 12-mounting hole, 13-motor coupling key, 14-spindle coupling key, 15-mass block coupling key, 16-aircraft model, 17-force balance. DETAILED DESCRIPTION

[0019] The implementation of the present invention is described in detail below in conjunction with the technical solutions and drawings.

[0020] Figure 1 This is the overall structure diagram of a wind tunnel model vibration inertia actuation suppression device of the present invention.

[0021] Figure 2 According to the actual test requirements, the motor 10 is a disc motor with low speed and high torque output characteristics.

[0022] During implementation, the end cap 2 and disc motor 10 are secured to the housing base 1 using the end cap set screws 3 and motor mounting screws 11, respectively. The bearing 4 is positioned via the housing base 1's shaft shoulder and the end cap. The coupling 9 is connected to the motor 10 via the motor coupling key 13 and to the spindle 5 via the spindle coupling key 14. The inertial mass 8 is secured axially by the positioning sleeve 7 and preload nut 6, and circumferentially by the mass coupling key 15. The active vibration suppression device is assembled through these steps.

[0023] Furthermore, the vibration inertia actuation suppression device is installed in the tail cavity of the aircraft model 16 through the six mounting holes 12 by means of bolt connection, and is coaxial with the force measuring balance 17, as shown in FIG. Figure 4 The installation diagram of the device of the present invention is shown in FIG.

[0024] Figure 3 The vibration suppression principle diagram of the device of the present invention is as follows. When implementing the control, two acceleration sensors are respectively arranged in the pitch and yaw orthogonal vibration directions at the center of mass of the model to collect the vibration signals of the pitch and yaw degrees of freedom, input them into the real-time controller, and obtain the pitch direction vibration force F f and the yaw vibration force F p By establishing the X-axis along the yaw vibration direction and the Y-axis along the pitch vibration direction, the vibration resultant force F can be obtained. h The angle θ between the direction of the motor and the positive direction of the X axis. The motor control mode is position control, and the control target is the motor angle θ d Compared with the vibration resultant force direction angle θ, it always lags behind by 180°. The controller outputs the control signal after real-time solution, drives the inertial mass block 8 to do circular motion and generates the same h The centrifugal inertia force F is reversed in real time. The centrifugal inertia force always does negative work on the structural vibration, acting as an additional damper to consume the structural kinetic energy, thereby reducing and suppressing the pitch and yaw composite vibration of the wind tunnel model. At the same time, the vibration amplitude attenuation of the model can be monitored in real time through an oscilloscope to observe the vibration state of the model.

[0025] Figure 5 This graph shows the vibration acceleration monitoring results of a hammer impact test on an aircraft model. After being subjected to a broadband load, the model experienced significant vibration at its natural frequencies in both the pitch and yaw vibration planes. The pitch and yaw vibration directions were perpendicular, with a fixed phase difference. The direction of their combined vibration acceleration varied periodically along the circumference. Using the device presented in this invention, by controlling the motor's rotation angle in real time to ensure that the direction of the inertial centrifugal force and the combined vibration acceleration are opposite in real time and change in a consistent pattern, the model's combined pitch and yaw vibration can be reduced and suppressed.

[0026] This invention describes a device for suppressing wind tunnel model vibration inertia. It effectively suppresses the model's pitch and yaw two-degree-of-freedom vibrations caused by airflow loads during wind tunnel testing, improving the accuracy of aerodynamic force measurement data. The device boasts a compact structure and simple control. Installation within the model's cavity avoids any additional impact on the model's aerodynamic shape, suggesting significant potential for application.

Claims

1. A wind tunnel model vibration inertia actuation suppression device, characterized in that: The wind tunnel model vibration inertia actuation suppression device comprises a housing base (1), an end cover (2), an end cover set screw (3), a bearing (4), a main shaft (5), a pre-tightening nut (6), a positioning sleeve (7), an inertial mass block (8), a coupling (9), a motor (10), a motor mounting screw (11) and a mass block connecting key (15); The housing base (1) is a cylindrical body with a circumferentially outwardly convex bottom, the outer surface of the top end of which is connected to the end cover (2) through the end cover set screw (3), and the inner surface of the bottom end is connected to the motor (10) through the motor mounting screw (11); a groove is provided at the top end of the housing base (1) for mounting the bearing (4); the lower end of the main shaft (5) is connected to the motor (10) through the coupling (9), and the upper end of the main shaft (5) passes through the housing base (1) and is connected to the bearing (4); the pre-tightening nut (6) and the positioning sleeve (7) are fixedly sleeved on the main shaft (5) in sequence; the inertial mass block (8) is in a "T" shape and performs a circular motion with the main shaft (5) as the center, and is axially fixed to the main shaft (5) through the pre-tightening nut (6) and the positioning sleeve (7), and is circumferentially fixed through the mass block connecting key (15); Six mounting holes (12) are evenly arranged on the outer convex portion of the bottom edge of the housing base (1) for mounting; a force balance (17) is located on the top side of the housing base (1); and the wind tunnel model vibration inertia actuation suppression device (18) and the force balance (17) are coaxially mounted in the tail cavity of the aircraft model (16).

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