Method for sound field separation by pressure velocity method

Abstract

The invention discloses a pressure speed method sound field separation method, a measured sound field is provided with a measuring surface S; a sound pressure sensor is adopted to measure the sound pressure on the measuring surface S, and a particle velocity sensor or a sound intensity probe is adopted to measure the particle speed on the measuring surface S; both sides of the measuring surface Sare provided with the imaginary source surfaces S1 <*> and S2 <*> which are provided with the equivalent sources; the transfer relationship between the equivalent sources and the sound pressure and the particle speed on the measuring surface S is constructed; the separation of sound source radiation sound pressure and the particle speed of both sides on the measuring surface according to the transfer relationship is realized; the sound field separation is realized by measuring the speed relation of sound pressure and particle on each surface; and the equivalent source method is adopted as thesound field separation arithmetic, the calculation stability is good, the calculation precision is high, and the implement is simple. The method can be widely applicable to the near-field acoustic holography measurement in the environments of internal sound field or noisy sound, the sound intensity method sound source identification in the noisy environment, the material reflection coefficient measurement, and the separation of the scattering sound field.

Description

Technical field: The invention relates to a sound field separation method in the field of noise in the physics profession, in particular to a pressure velocity method sound field separation method. Background technique: In actual measurement, it is usually encountered that there are sound sources on both sides of the measurement surface, or there is reflection or scattering on one side of the measurement surface. In actual engineering, in order to more accurately study the sound radiation characteristics of the actual sound source or the reflection characteristics of the reflective surface, it is necessary to separate the radiated sound from both sides of the measurement surface. In 1980, G.Weinreich et al proposed to use two methods of measuring very close to the measuring surface to realize the separation of incident wave and radiation wave. Based on the near-field acoustic holography technology proposed by E.G.Williams et al. and the double-surface measurement method pro...

AI Technical Summary

Problems solved by technology

The sound field separation method based on the spatial FFT method has its inherent defects: on the one hand, the shape of the measurement surface is limited, that is, it can only be a regular shape such as a plane, cylinder or sphere; on the other hand, it is affected by the FFT algorithm. The separation error is large, especially when the sound pressure difference from both sides of the measurement surface is large, the error is particularly obvious

Defects of this method: there are restrictions on the shape of the measurement surface, that is, it can only be a regular shape such as a plane, a cylinder or a sphere

Defects of this method: there are singular integrals, non-uniqueness of solutions, etc., and the calculation efficiency is low

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