An anechoic chamber for suppressing far-field low-frequency pressure fluctuations in an open jet wind tunnel

Abstract

The present invention discloses an anechoic chamber for inhibition of opening jet flow wind tunnel far field low-frequency pressure pulses. The chamber comprises a front side wall, a rear side wall, atop wall, a bottom wall, a left end side wall and a right end side wall. The bottom wall is arranged on a horizontal plane, the front side wall, the rear side wall, the left end side wall and the right end side wall are vertically arranged on the bottom wall, the front side wall, the right end side wall, the rear side wall and the left end side wall are connected end to end to form a periphery wall, and the top wall is horizontally covered at the top portions of the front side wall, the rear side wall, the left end side wall and the right end side; the front side wall and the rear side wall form an angle of inclination relative to the right end side wall to form a space structure which is gradually enlarged from the left end to the right end, wherein widths of difference sections of the space structure are gradually enlarged in an air flow direction. The anechoic chamber for inhibition of opening jet flow wind tunnel far field low-frequency pressure pulses can avoid or minimize the pressure standing-wave resonance as little as possible so as to greatly reduce the wind tunnel anechoic chamber far field low-frequency pressure pulses and facilitate secondary construction of a currentwind tunnel anechoic chamber.

Description

technical field [0001] The invention belongs to the technical field of wind tunnel experimental devices, in particular to an anechoic chamber for suppressing far-field low-frequency pressure fluctuations in an open jet wind tunnel. Background technique [0002] Low-frequency pressure pulsation is a common phenomenon in open-jet wind tunnels. Its typical manifestation is that under a specific test wind speed, there are strong low-frequency pressure fluctuations in the jet flow of the wind tunnel and the anechoic chamber, which are approximately single-frequency characteristics. Low-frequency pressure fluctuations damage the quality of the flow field and seriously affect the accuracy of the aerodynamic and aeroacoustic measurements of the test model. In order to carry out high-quality aerodynamic and aerodynamic noise experimental research in the open jet wind tunnel, it is particularly important to control the low-frequency oscillation of the jet wind tunnel and obtain a rel...

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Problems solved by technology

However, the anechoic chamber of the existing open jet wind tunnel is basically a cubic structure, and the widths of different cross-sections along the flow direction are equal, which will cause the pressure standing wave of the jet in the width direction to have the same frequency in each cross-section. If it is consistent with the natural frequency of the anechoic chamber, strong structural resonance will occur, which will cause huge fluid noise and cause serious low-frequency pressure fluctuations in the entire anechoic chamber, which seriously restricts advanced aircraft / high-speed trains / automobiles, etc. The need for high-quality test results

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