A full-mold support device for large-scale low-speed wind tunnel flutter test

Abstract

The invention discloses a large-scale low-speed wind tunnel flutter test full-model support device, comprising a model suspension frame and a plurality of steel cables, a position adjustment mechanism is installed on the model suspension frame, one end of two vertical steel cables is respectively connected to the position adjustment mechanism through a group of suspension springs, and the other end is connected to the model fuselage; the upper and lower ends of the two front steel cables are respectively fixedly connected to the upper and lower walls of the wind tunnel; the upper ends of the two rear steel cables are respectively fixedly connected to the upper wall of the wind tunnel, the lower end of each rear steel cable sequentially passes through the lower wall connection pulley on the corresponding side, the lower wall of the wind tunnel, the counterweight connection pulley and a group of counterweight groups, the two transverse steel cables are respectively fixedly connected to the left and right sides of the model fuselage, the two ends of each transverse steel cable are respectively connected to the front and rear steel cables, and the transverse steel cables are combined with the counterweights to tighten the front and rear steel cables toward the model direction, so that the model can move in multiple directions. The invention has small additional mass and small aerodynamic interference on the model, and is suitable for different models.

Description

Technical Field

[0001] The invention relates to a large-scale low-speed wind tunnel flutter test full-mold supporting device. Background Art

[0002] Flutter is a very dangerous vibration caused by aeroelasticity, with no attenuation of aircraft components and a large amplitude. For aircraft, flutter often leads to catastrophic consequences such as aircraft destruction and loss of life, so determining the critical flutter speed of an aircraft is a crucial part of aircraft design. At the current level of technology, it is too dangerous and costly to conduct flutter tests entirely on real aircraft, so model flutter wind tunnel tests still play an important role in flutter analysis.

[0003] Wind tunnel flutter tests include single component flutter tests, combined component flutter tests, and full-model flutter tests. When the coupling between components is large, using component models to conduct flutter tests to verify the flutter characteristics of the aircraft can meet engineering needs. However, with the development of material technology and increasingly high structural optimization requirements, the stiffness of each component is getting closer and closer, and the mutual influence between components is becoming more and more complex, resulting in the flutter characteristics of the aircraft can no longer be obtained using one or several components. Therefore, the full-model flutter test is an indispensable test project for the development of new aircraft.

[0004] The model support device is one of the core components of the flutter full-aircraft model test. In the full-aircraft flutter test, it is required to simulate the free flight state of the real aircraft. For example, some flutter forms may be caused by the coupling of rigid body motion modes and structural elastic modes. The dynamic characteristics of this type of flutter form will be affected by the constraint load of the support device, resulting in serious deviations in the flutter test results. However, if the support device is required to allow arbitrary free rigid body motion of the model, it is difficult for the designed support device to ensure the safety of the model and the wind tunnel.

[0005] In the low-speed flutter full-mold test, when the model is approaching or experiencing flutter, the support system may have additional mass in the flutter mode, and some support devices have a large aerodynamic interference on the model. The above-mentioned flutter test full-mold support devices will affect the accuracy of the test results. Summary of the invention

[0006] In order to solve the above problems, the purpose of the present invention is to provide a large-scale low-speed wind tunnel flutter test full-model support device, which has small additional mass and aerodynamic interference to the model and is suitable for different models.

[0007] The present invention is mainly realized through the following technical scheme: a large-scale low-speed wind tunnel flutter test full-model support device, including a model suspension frame and a plurality of steel cables, the model suspension frame is installed on the upper wall of the wind tunnel, the model suspension frame is installed with a longitudinal and lateral position adjustment mechanism, one end of two vertical steel cables are respectively connected to the longitudinal and lateral position adjustment mechanism through a group of suspension springs, and the other ends of the two vertical steel cables are connected to the model fuselage; located in front of the left and right sides of the fuselage, the upper and lower ends of the two front steel cables are respectively fixedly connected to the upper wall of the wind tunnel and the lower wall of the wind tunnel; located behind the left and right sides of the model fuselage, the upper surface of the lower wall of the wind tunnel is respectively fixed with two groups of lower wall connecting pulleys, and the lower wall of the wind tunnel is respectively fixed with two groups of lower wall connecting pulleys. Two groups of counterweight connecting pulleys are fixed on the lower surface of the tunnel wall, the upper ends of the two rear steel cables are fixedly connected to the upper tunnel wall of the wind tunnel, the lower end of each rear steel cable passes through the lower tunnel wall connecting pulley on the corresponding side, the lower tunnel wall of the wind tunnel, the counterweight connecting pulley and a group of counterweight groups in sequence, the two transverse steel cables are fixedly connected to the left and right sides of the model fuselage, the front end of each transverse steel cable is connected to the front steel cable on the corresponding side through the steel cable connecting pulley, and the rear end of each transverse steel cable is connected to the rear steel cable on the corresponding side through the steel cable connecting pulley. The two transverse steel cables are combined with the two groups of counterweight groups to tighten the two front steel cables and the two rear steel cables toward the model, so that the model can have multiple directional movements of heave, pitch and yaw.

[0008] The present invention also has the following technical feature: the suspension spring is located outside the upper wall of the wind tunnel.

[0009] Advantages and beneficial effects of the present invention: The present invention can realize the heave, pitch, yaw and other multi-directional movements of the model, can fully release the model's degree of freedom, and can also ensure the safety of the model and the wind tunnel; the suspension frame is designed as two sections, and is connected by screws, which is convenient for disassembly and assembly; the suspension spring is located outside the upper wall of the wind tunnel, realizing the "soft support" of the model, fully decoupling the structural elastic vibration mode and rigid body mode of the model, and ensuring the accuracy of the test data. This steel cable tensioning support method has a small additional mass and aerodynamic interference to the model, and is suitable for different models. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is the front view of the present invention.

[0011] Figure 2 It is a side view of the present invention.

[0012] Figure 3 This is a detailed view of the part below the model suspension bracket.

[0013] Figure 4 This is a top view of the model suspension device.

[0014] Among them, 1. lateral position adjustment mechanism, 2. longitudinal position adjustment mechanism, 3. suspension spring, 4. model suspension frame, 5. upper wall of wind tunnel, 6. vertical steel cable, 7. front steel cable, 8. lateral steel cable, 9. model, 10. rear steel cable, 11. lower wall of wind tunnel, 12. counterweight group, 13. steel cable connecting pulley, 14. lower wall connecting pulley, 15. counterweight connecting pulley, 16. counterweight adjustment block hoisting rod, 17. counterweight adjustment block, 21. longitudinal and lateral position adjustment mechanism installation plate, 22. diagonal support beam of the upper part of the model suspension frame, 23. guardrail, 24. upper and lower support plates of the model suspension frame, 25. lower support vertical beam of the model suspension frame, 26 , the diagonal bracing beam of the lower part of the model suspension frame, 27, the rib plate, 28, the base of the suspension frame, 29, the ladder, 31, the upper position adjustment plate of the front steel cable, 32, the upper lifting ring of the front steel cable, 33, the upper tensioner of the front steel cable, 34, the upper position adjustment plate of the rear steel cable, 35, the upper lifting ring of the rear steel cable, 36, the upper tensioner of the rear steel cable, 37, the lower tensioner of the front steel cable, 38, the lower lifting ring of the front steel cable, 39, the lower position adjustment plate of the front steel cable, 41, the guardrail, 42, the linear module of the longitudinal position adjustment mechanism, 43, the motor of the longitudinal position adjustment mechanism, 44, the motor of the lateral position adjustment mechanism, 45 the linear module of the lateral position adjustment mechanism. DETAILED DESCRIPTION

[0015] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings:

[0016] Example 1

[0017] like Figure 1-3As shown, a large-scale low-speed wind tunnel flutter test full-model support device comprises a model suspension frame and a plurality of steel cables, characterized in that the model suspension frame is installed on the upper wall of the wind tunnel, the model suspension frame is installed with a longitudinal and lateral position adjustment mechanism, one end of two vertical steel cables are respectively connected to the longitudinal and lateral position adjustment mechanism through a group of suspension springs, and the other ends of the two vertical steel cables are connected to the model fuselage; located in front of the left and right sides of the fuselage, the upper and lower ends of the two front steel cables are respectively fixedly connected to the upper wall of the wind tunnel and the lower wall of the wind tunnel; located behind the left and right sides of the model fuselage, the upper surface of the lower wall of the wind tunnel is respectively fixed with two groups of lower wall connecting pulleys, and the lower surface of the lower wall of the wind tunnel is respectively fixed with There are two groups of counterweight connection pulleys. The upper ends of the two rear steel cables are fixedly connected to the upper wall of the wind tunnel. The lower end of each rear steel cable passes through the lower wall connection pulley on the corresponding side, the lower wall of the wind tunnel, the counterweight connection pulley and a group of counterweight groups in turn. The two transverse steel cables are fixedly connected to the left and right sides of the model fuselage respectively. The front end of each transverse steel cable is connected to the front steel cable on the corresponding side through the steel cable connection pulley, and the rear end of each transverse steel cable is connected to the rear steel cable on the corresponding side through the steel cable connection pulley. The two transverse steel cables are combined with the two groups of counterweight groups to tighten the two front steel cables and the two rear steel cables toward the model, forming a "V" shape, so that the model can have multiple directions of heave, pitch and yaw. It can fully release the model's degree of freedom and at the same time ensure the safety of the model and the wind tunnel.

[0018] like Figure 4 As shown, the longitudinal and lateral position adjustment mechanisms are both composed of servo motors and linear modules thereof, which make the model move more steadily and the position adjustment more precise. The longitudinal and lateral position adjustment mechanisms adjust the model to the specified position during the test, and adjust the model to a position convenient for test participants to operate when the test is over or the test state is changed. The model suspension frame is equipped with guardrails and ladders to ensure the safety of the commissioning personnel; the support frequency of the model suspension frame is more than twice the natural frequency of the first-order elastic mode of the model, which completely avoids the disadvantage that the model suspension frame affects the interaction between the elastic modes of the model structure; the model suspension frame is 5m high, and the suspension spring is located outside the upper wall of the wind tunnel, realizing a "soft support" method, which is suitable for different types of flutter full-model tests.

Claims

1. A large-scale low-speed wind tunnel flutter test full-mold support device, comprising a model suspension frame and a plurality of steel cables, characterized in that: The model suspension frame is installed on the upper wall of the wind tunnel, and a longitudinal and lateral position adjustment mechanism is installed on the model suspension frame. One end of two vertical steel cables is connected to the longitudinal and lateral position adjustment mechanism through a group of suspension springs, and the other end of the two vertical steel cables is connected to the model fuselage; located in front of the left and right sides of the fuselage, the upper and lower ends of the two front steel cables are respectively fixedly connected to the upper wall of the wind tunnel and the lower wall of the wind tunnel; located behind the left and right sides of the model fuselage, the upper surface of the lower wall of the wind tunnel is respectively fixed with two groups of lower wall connecting pulleys, and the lower surface of the lower wall of the wind tunnel is respectively fixed with two groups of counterweight connecting pulleys, and the two rear steel cables are respectively fixed with two groups of counterweight connecting pulleys. The upper end of the cable is fixedly connected to the upper wall of the wind tunnel, the lower end of each rear steel cable passes through the lower wall connecting pulley on the corresponding side, the lower wall of the wind tunnel, the counterweight connecting pulley and a group of counterweight groups in sequence to be connected, the two transverse steel cables are fixedly connected to the left and right sides of the model fuselage respectively, the front end of each transverse steel cable is connected to the front steel cable on the corresponding side through the steel cable connecting pulley, and the rear end of each transverse steel cable is connected to the rear steel cable on the corresponding side through the steel cable connecting pulley, the two transverse steel cables are combined with the two groups of counterweight groups to tighten the two front steel cables and the two rear steel cables toward the model, so that the model can have multiple directional movements of heave, pitch and yaw.

2. A large-scale low-speed wind tunnel flutter test full-mold support device according to claim 1, characterized in that: The suspension spring is located outside the upper wall of the wind tunnel.

Images