Free field restoration method of unstable state planar sound source

An unsteady state, sound source technology, applied to the measurement of ultrasonic/sonic/infrasonic waves, measuring devices, instruments, etc., can solve the problem of unsteady scattering sound fields that cannot eliminate interfering sound

Active Publication Date: 2017-12-15
ANHUI UNIVERSITY
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Problems solved by technology

[0005] However, these time-domain separation methods can only remove the unsteady sound field produced by the interfering sound source on the other side of

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  • Free field restoration method of unstable state planar sound source
  • Free field restoration method of unstable state planar sound source
  • Free field restoration method of unstable state planar sound source

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Embodiment Construction

[0063] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0064] The present invention is a free-field restoration method of an unsteady plane sound source, which is characterized in that two measurement planes are arranged between the target sound source and the interference sound source, and the time-domain sound at each grid point on the two measurement planes is collected synchronously. pressure signal; the time-domain sound pressure signals on the two measurement planes are subjected to two-dimensional spatial Fourier transform to obtain the time-domain wavenumber spectrum of the sound pressure at each wavenumber on the corresponding surface; and then the time-domain sound pressure on the two measurement planes is used The wave number spectrum and the time-domain impulse response function between the known sound pressure and the sound pressure, the unsteady outward sound field (including the unste...

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Abstract

The present invention discloses a free field restoration method of an unstable state planar sound source. Time-domain sound pressure signals on two measurement planes are subjected to two-dimensional space Fourier transform to obtain sound pressure time-domain wave number spectrums at each wave number on corresponding planes; the two sound pressure time-domain wave number spectrums on the measurement planes and a time-domain pulse response function between known sound pressures are employed to separate from an unstable state outward sound field and an unstable state inward sound field; a target sound source surface reflection coefficient is taken as a boundary condition to establish a relation of the unstable state inward sound field and a scattering sound field and calculate an unstable state scattering sound field; and the unstable state scattering sound field is removed from the separated unstable state outward sound field, and the time-domain sound pressure signals radiated on the measurement planes in the target sound source free field condition is restored. The free field restoration method of the unstable state planar sound source eliminates the unstable scattering sound on the time domain and restores the time-domain sound pressure radiated on the measurement planes in the target sound source free field condition so as to provide a pre-processing means for accurate analysis of the time variation radiation features and vibration features of the target sound source in the real sound field environment.

Description

technical field [0001] The invention relates to the field of noise in physics specialty, in particular to a free-field restoration method of an unsteady plane sound source. 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: Hu et al. derived a complete calculation formula for planar near-field acoustic holography b...

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Application Information

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IPC IPC(8): G01H17/00
CPCG01H17/00
Inventor 耿林
Owner ANHUI UNIVERSITY
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