Free field real-time restoring method for non-steady state plane sound source measured by sound pressure and particle acceleration

Abstract

The invention discloses a free field real-time restoring method for a non-steady state plane sound source measured by sound pressure and particle acceleration. The free field real-time restoring method for the non-steady state plane sound source measured by sound pressure and particle acceleration comprises the steps of carrying out finite difference on time-domain sound pressure on a measurementplane H and an auxiliary measurement plane H1 to obtain time-domain particle acceleration on the plane H, and carrying out two-dimensional space Fourier transform to obtain a sound pressure and particle acceleration time-domain wavenumber spectrum on the plane H; and then deducing a free-field restoring formula by utilizing the sound pressure time-domain wavenumber spectrum and the particle acceleration time-domain wavenumber spectrum on the plane H, a known time-domain impulse response function between the sound pressure and the particle acceleration and between sound pressures, and a surfacereflection coefficient of a target sound source, and recovering a time-varying sound pressure signal radiated on the plane H under the free-field condition of the target sound source in real time. According to the method, the influence of the non-steady state scattering sound field is eliminated in the time domain, any inversion and regularization operation processing is not needed, the capability of restoring the sound field in real time is achieved, and the method can be used for analyzing the time-varying radiation characteristic and the vibration characteristic of the target sound sourceon site in an actual sound field environment.

Description

technical field [0001] The invention relates to the field of noise in the specialty of physics, in particular to a free-field real-time restoration method of an unsteady plane sound source measured by sound pressure and particle acceleration. Background technique [0002] The actual sound field environment is a non-free field, which includes not only the radiated sound of the target sound source, but also the interference sound from the other side of the measurement surface and the scattered sound generated by the interference sound on the surface of the target sound source. In addition to the sound field produced by the interfering sound that can affect the sound field radiated by the target sound source, the scattered sound can also affect the accurate measurement of the radiated sound field of the target sound source. eliminated from the results. [0003] So far, scholars at home and abroad have proposed a variety of free-field restoration methods: Hald et al. proposed a...

AI Technical Summary

Problems solved by technology

In this unsteady-state reduction method, the relationship between the time-domain sound pressure radiated by the target sound source in the free field and the mixed time-domain sound pressure on the double measurement surfaces cannot be directly established. It is necessary to separate the unsteady-state sound field first, and then to Unless the sound field is scattered in a steady state, real-time restoration cannot be achieved; this restoration method still requires complex iterative unconvolution calculations, and its process is an ill-conditioned inverse problem, which requires Tikhonov regularization and singular value decomposition to obtain a suitable solution, resulting in the reduction method calculation The amount is large, and the restoration accuracy largely depends on the reasonable selection of regularization parameters; the distance between the two measurement surfaces also affects the restoration accuracy

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