Sound field separating method based on single-surface measurement and local acoustical holography method

Abstract

The invention relates to the field of noise, in particular to a sound field separation and reconstruction method applicable to sound field separation and reconstruction of large sound sources. The sound field separation and reconstruction method comprises the following steps of: acquiring sound pressure and normal particle vibration velocity on a measuring surface; performing zero filling extension on the measuring surface positioned between two sound sources; acquiring transfer matrixes between the extended measuring surface and surfaces of the two sound sources, namely sound source faces; building a transitive relation between the sound pressure and the normal particle vibration velocity on the measuring surface; and acquiring the sound pressure and the normal particle vibration velocity of the first sound source face and the sound pressure and the normal particle vibration velocity of the second sound source face. A sound field is separated and reconstructed by using the single-measurement-surface and local near-field acoustical holography method. The sound field separation and reconstruction method has the characteristics of simplicity, short calculation time and high calculation efficiency, and can be widely applied to the measurement of near-field acoustical holography, the measurement of material reflecting coefficients, the separation of scattering sound fields and the like of large-size sound-source sound fields.

Description

technical field [0001] The invention relates to the field of noise, in particular to a sound field separation and reconstruction method suitable for the separation and reconstruction of large sound sources. Background technique [0002] 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 target 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. Existing separation methods include: (1) Single-sided sound field separation technology based on Fourier transform ("Acta Physica Acta" (2009, Vol. 58, No. 12)). This method can remove the singularity, and can use single-surface measurement for sound field separation. The disadvant...

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Problems solved by technology

This method can remove the singularity, and can use single-surface measurement for sound field separation. The disadvantage of this method is that it is affected by the Fourier transform algorithm, and accurate separation results can only be obtained when the aperture of the measurement surface is at least several times the size of the reconstruction surface. Therefore, the amount of measurement is large, and it is impossible to separate large-scale sound sources. Even if the sound field separation results can be obtained, the sound field reconstruction of the sound source surface still needs to be continued; (2) Sound field separation technology based on double-sided vibration velocity measurement (Acta Acoustica Sinica "(Volume 35, Issue 6, 2010))

This method first measures the normal particle velocity on two parallel and equidistant measuring surfaces, and then uses the Fourier method to separate the incident and radiated sound fields. This method can obtain higher accuracy of the normal particle velocity, but it is still subject to measurement Aperture size limitation; (3) Statistically optimal sound field separation method based on sound pressure and velocity measurements

In the article of "J.Acoust.Soc.Am" (2007, Volume 121, Issue 3), Jacobsen et al. proposed a statistically optimal sound field separation method based on sound pressure and velocity measurements. This method uses a p-u sound intensity probe to measure Measure the local sound pressure and particle velocity information on the surface, and then use the established joint solution formula to realize the separation of the radiation sound field from both sides of the measurement surface and the reconstruction of the sound source surface. This method solves the limitation of the measurement space size, but its The disadvantage is that the calculation is large, the efficiency is low, and the calculation time is long

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