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A Cavity Modal Noise Standing Wave Decomposition Method

A cavity mode and modal technology, applied in the field of experimental fluid mechanics, can solve the problem of not being able to reflect the distribution of modal noise

Active Publication Date: 2019-05-24
INST OF HIGH SPEED AERODYNAMICS OF CHINA AERODYNAMICS RES & DEV CENT
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The sound pressure spectrum reflects the distribution of noise in frequency, but it is only for the data of a single measuring point, so it cannot reflect the distribution of modal noise in space

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  • A Cavity Modal Noise Standing Wave Decomposition Method
  • A Cavity Modal Noise Standing Wave Decomposition Method
  • A Cavity Modal Noise Standing Wave Decomposition Method

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Embodiment Construction

[0023] The present invention proposes a standing wave decomposition method of cavity modal noise, which uses the standing wave theory to analyze the distribution law of cavity modal noise, including the following contents:

[0024] 1) Modal noise decomposition

[0025] Spectrum analysis is performed on the time-domain information obtained by the pulsating pressure sensor. Since the modal noise is mainly generated from the trailing edge, from the sound pressure spectrum of the pulsating pressure at the measuring point on the trailing edge, the peak characteristics of the curves can be used to distinguish the different modal noises. frequency and sound pressure amplitude. Modal noise propagates in the cavity in the form of sound waves, and its frequency remains basically unchanged during the propagation process. Therefore, the sound pressure levels of the same modal frequency at different measurement points in the cavity noise are all caused by the modal noise. The sound pressu...

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Abstract

The invention discloses a novel decomposition method for standing waves of modal noise of a cavity. The method comprises the following steps that 1, by means of the frequency spectrum features of pulsating pressure data of different measuring points of the bottom surface of the cavity, the modal noise is decomposed to obtain spatial distribution of the amplitude of the different modal noise; 2, bymeans of spatial distribution of the amplitude of the modal noise of the bottom surface of the cavity, the forms of the modal standing waves are determined. Compared with the prior art, the method has the advantages that the novel analysis method for the standing waves of the modal noise aims at the pulsating pressure data of the inner wall surface of the cavity; according to the method, by meansof sound pressure frequency spectra of the measuring points of the wall surface of the cavity, spatial distribution of the different modal noise in the cavity is extracted, and through a standing wave theory, the standing wave distribution rule of the modal noise is analyzed.

Description

technical field [0001] The present invention relates to the field of experimental fluid mechanics, in particular to a standing wave decomposition method of cavity modal noise, which realizes the analysis of the distribution law and radiation characteristics of the modal noise in the cavity by decomposing the physical process of the formation and propagation of the cavity standing wave analyze. Background technique [0002] When the high-speed air flow passes through the cavity, a shear layer is formed above the cavity due to flow separation. There are multi-scale vortices in the shear layer, which generate high-intensity noise when they collide with the rear edge of the cavity. Vibration brings about structural fatigue damage, which in turn affects the service life and safety of the structure, and also affects the normal operation of equipment in the aircraft. In addition, noise pollution can also affect the health of personnel. Therefore, it is of great significance to stu...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G01M9/00G01M9/02G06F17/50
CPCG01M9/00G01M9/02G06F30/15G06F30/20Y02T90/00
Inventor 杨党国周方奇路波吴军强刘俊王显圣施傲杨野郑晓东
Owner INST OF HIGH SPEED AERODYNAMICS OF CHINA AERODYNAMICS RES & DEV CENT