Method for sound field separation by double plane vibration speed measurement and two dimensional space Fourier transform
A Fourier transform and two-dimensional space technology, applied in the field of noise, can solve the problems of low precision of normal particle vibration velocity and large separation error
Inactive Publication Date: 2011-03-16
HEFEI UNIV OF TECH
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[0003] The two-dimensional spatial Fourier transform method is used as the sound field separation algorithm, which has the advantages of fast calculation speed and simple implementation; however, due to the limitation of the Fourier transform algorithm, the shape of the measurement surface can only be a regular shape such as a plane, cylinder or sphere, and the separation error Too big
In particular, the existing sound field separation technology based on double-sided sound pressure measurement and the two-dimensional space Fourier transform method uses the sound pressure on the two measurement surfaces as the input for separation. The separated sound pressure has high accuracy, but the separated The normal particle velocity accuracy is relatively low
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[0096] See figure 1 In this embodiment, sound sources are distributed on both sides of the measurement surface, among which sound source 1 is the main sound source, and sound source 2 is a noise source or a reflection or scattering source. In the measured sound field composed of sound source 1 and sound source 2, In, there is a measuring surface S between sound source 1 and sound source 2 1 , On the measuring surface S 1 Set a measurement surface S between the sound source 2 1 Auxiliary measuring surface S parallel and separated by δh 2 ; There are measuring grid points distributed on the two measuring surfaces respectively, and the distance between adjacent grid points is less than half a wavelength; the δh value is not zero and not greater than the minimum interval of the measuring grid points.
[0097] The specific implementation steps are:
[0098] a. Use single or multiple mass point vibration velocity sensors to scan on the two measurement surfaces respectively, use the mass ...
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The invention provides a method for sound field separation by double plane vibration speed measurement and two dimensional space Fourier transform, which is characterized in that a measurement plane S1 and an auxiliary measurement plane S2 parallel therewith and Delta h away therefrom are disposed in the measurement sound field; normal direction particle vibration speed is measured on two planes;wave number domain transfer relationship between normal direction particle vibration speed on two measurement planes is established by the two dimensional space Fourier transform; sound pressure, normal direction particle vibration speed radiated by sound sources on both sides of the two measurement planes is separated according to the transferring relation. The method adopts two dimensional spaceFourier transform as the sound field separation algorithm, making computation speed fast, and implementation simple; normal direction particle vibration speed on two measurement plane is used as theinput for separation, so that the separated normal direction particle vibration speed has higher accuracy comparing with using sound pressure on two measurement planes as the input. The method can bewidely applied for near-field acoustic holographic measurement under internal sound field or noise environment, material reflection coefficient measurement, scattering sound field separation.
Description
Technical field [0001] The invention relates to a sound field separation method in the field of noise in the physics specialty. 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 reflecting surface, it is necessary to separate the radiated sound from both sides of the measuring surface. The sound field separation technology based on double-sided sound pressure measurement and two-dimensional space Fourier transform method is an effective method proposed by GVFrisk et al. on the basis of the near-field acoustic holography technology proposed by EG Williams et al. and the double-sided method proposed by G. Weinreich et al. The sound field separation ...
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IPC IPC(8): G01H5/00G01H17/00
Inventor 毕传兴张永斌徐亮陈心昭
Owner HEFEI UNIV OF TECH