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An airfoil two-degree-of-freedom dynamic wind tunnel test device

A technology of wind tunnel test and degree of freedom, applied in the field of wind tunnel test, can solve problems such as vibration balance angle of attack and amplitude stepless control and adjustment, high load, vibration, etc.

Active Publication Date: 2020-07-07
LOW SPEED AERODYNAMIC INST OF CHINESE AERODYNAMIC RES & DEV CENT
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] For helicopters, dynamic stall is accompanied by rapid changes in the aerodynamic load on the blades in a short period of time, and the resulting problems include: high load, vibration, blade flutter, sudden noise, etc., which seriously limit the The carrying capacity, flight speed and maneuverability of the helicopter, etc.
However, the technology disclosed in this patent can only realize the pitch oscillation of the airfoil in one degree of freedom, and the online stepless control and adjustment of the oscillation balance angle of attack and amplitude cannot be performed, and the drive structure (that is, the crank connecting rod ) can only be adjusted by replacement, and this solution cannot be realized for more degrees of freedom, such as ups and downs, so the existing technology cannot meet the more requirements of wind tunnel tests

Method used

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  • An airfoil two-degree-of-freedom dynamic wind tunnel test device
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  • An airfoil two-degree-of-freedom dynamic wind tunnel test device

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] When the model performs a pitching single-degree-of-freedom motion with large amplitude, high frequency, and high Mach number, in order to avoid impact and damage to the linear motor, and the unequal displacement between the slider and the guide rail of the linear motor on both sides is likely to cause two The side servo motors are not on the same axis, which will cause damage to the servo motor and deformation of the model. Therefore, it is necessary to fix the primary sides on both sides firmly with bolts or pins.

[0038] On the premise of ensuring that the model has sufficient rigidity and strength, in order to meet the requirements of high dynamics and high precision of the system, the model is made of carbon fiber material, plus the mass of the balance, sensors, cables, etc. is 20kg in total, and the moment of inertia of the load is 0.1kg•m2 . The indicators used in the design: the amplitude of the pitching motion is 15°, the frequency is 5Hz, the test wind speed ...

Embodiment 2

[0041] When the model only performs single-degree-of-freedom movement of ups and downs, due to the limitation of the load movement capacity of the largest linear motor, it is necessary to remove the pitching mechanism from the primary to reduce the moving mass of the linear motor to achieve large amplitude, high frequency and high Mach number of design indicators.

[0042] The indicators used in the design: the amplitude is 0.13m, the frequency is 4Hz, the test wind speed is 0.2Ma, the movement path is planned according to the cosine curve s=Acos(2πft), the load force of the motor is the load force of the mechanism movement and the superimposed lift force (it is specified that the model is positive upward Direction), since the movement mode is vertical movement, the influence of gravity also needs to be considered. Driven by two motors, the efficiency is generally 0.9, the design safety margin is 30% (generally 20%~30%), and the total thrust of the linear motor is F 总 =m×(a+g...

Embodiment 3

[0044] When the model performs coupling motion, the pitching motion mechanism is installed on the primary of the linear motor, and moves up and down together with the sinking motion mechanism, but the motion amplitude and frequency will be limited. Coupling motion means that two servo motors and two linear motors generally move together at the same frequency and respective amplitudes, and the maximum index that can be achieved depends on the specific debugging results.

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Abstract

The invention discloses an airfoil profile two-freedom dynamic wind tunnel testing device which comprises a supporting frame. The supporting frame comprises a left supporting column and a right supporting column. The two supporting columns are respectively provided with an up-and-down motion module. Each up-and-down motion module is provided with a pitching motion module. Two ends of a tested airfoil profile are connected with one pitching motion module. When the pitching motion module performs simultaneous motion, the up-and-down motion module performs synchronous motion, thereby driving a tested model for realizing pitching and up-and-down coupling oscillation. The airfoil profile two-freedom dynamic wind tunnel testing device breaks through great technological problems such as statics and dynamics simulation optimization design of an airfoil profile oscillation device, safe synchronous control of a motor power system and pitching / up-and-down two-freedom motion path planning, and canrealize pitching and up-and-down motion, and rotor aerofoil profile low-speed dynamic aerodynamic characteristic testing capability in pitching and up-and-down coupling oscillation motion.

Description

technical field [0001] The invention relates to the field of wind tunnel tests, in particular to an airfoil two-degree-of-freedom dynamic wind tunnel test device. Background technique [0002] For helicopters, dynamic stall is accompanied by rapid changes in the aerodynamic load on the blades in a short period of time, and the resulting problems include: high load, vibration, blade flutter, sudden noise, etc., which seriously limit the The carrying capacity, flight speed and maneuverability of the helicopter, etc. Improving the dynamic stall characteristics is the key to realize the high-maneuvering flight of armed helicopters and the high-speed flight of heavy-loaded transport helicopters. Rotor dynamic stall is a serious unsteady aerodynamic phenomenon, its mechanism is very complex, and the dynamic stall of the airfoil is its concentrated expression. A deep understanding of the dynamic stall characteristics of the rotor airfoil is conducive to the study of how to improve...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01M9/06G01M9/02
CPCG01M9/02G01M9/06
Inventor 张卫国李国强孔鹏康洪铭陈辅政顾艺赵亮亮唐乔乔孙福振
Owner LOW SPEED AERODYNAMIC INST OF CHINESE AERODYNAMIC RES & DEV CENT