Closed space panel acoustic contribution degree identification method

Abstract

The invention discloses a closed space panel acoustic contribution degree identification method. According to the method, a holographic measurement surface close to an inner surface is set at an internal portion of the closed space, sound pressure sensors are arranged on the measurement surface in a mesh mode, and the distance between adjacent grid points is less than half a wavelength; the orthogonal spherical wave superposition method is utilized to establish the transfer relationship between the sound pressure at the measurement surface and source strength of an orthogonal spherical wave source, and the source strength of the orthogonal spherical wave source is calculated; according to the source strength of the orthogonal spherical wave source, the relationship between the surface normal vibration velocity of the closed space structure and the source strength of the orthogonal spherical wave source is established; the acoustical contribution degree of a closed space panel is calculated through utilizing the sound field equivalence principle. The method is advantaged in that the method is suitable for closed sound fields in any shapes, the quantity of required measurement pointsis small, the method is simple and convenient for enforcement; due to mutual orthogonality of different orders of the orthogonal spherical wave source, the ill conditioning property of a transfer matrix is reduced, and computation accuracy is greatly improved.

Description

technical field [0001] The invention relates to the field of noise source identification methods, in particular to a method for identifying acoustic contribution degrees of panels in closed spaces based on orthogonal spherical wave superposition. technical background [0002] The spatial sound field formed by the vibration of a complex elastic closed cavity structure under external excitation is the most representative type of sound field in engineering practice, such as the cabin sound field of automobiles, ships and aircraft. With the continuous improvement of people's requirements for the comfort of living and working environments, the noise problem inside the closed space structure has been paid more and more attention by people. After the external excitation energy is transmitted to the closed cavity structure, each panel vibrates and then radiates structural noise into the acoustic cavity, which finally affects the interior of the closed space. The main factors of its ...

AI Technical Summary

Problems solved by technology

This method reconstructs the entire sound field information through a set of holographic sound pressure measurements, and uses the sound field equivalent principle to solve the acoustic contribution of each vibrating panel of the closed structure to any position in the cavity. The full-field acoustic measurement of the entire closed space requires a large number of measurement points, which increases the measurement cost and has the problem of selecting the equivalent source position.

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