Influences on Spatial Directivity of Acoustic Vector Sensor by Soft Spherical Boundary

Abstract

In the free field, making full use of scalar and vector information of acoustic field can bring many advantages for acoustic measurement, but under the conditions of the existence of sound baffle, the sound field should be distorted due to the superposition of diffraction wave. Taking the soft spherical baffle as background, the sphere scattering model is established, the diffraction pressure field and particle velocity field under the condition of different frequency, distance and incident angle is analyzed. The effect of diffraction wave on sound pressure and particle velocity is determined by the amplitude of diffraction wave and the phase difference between the diffraction wave and the incident wave, which is related with the frequency, distance and incident angle. The effect of diffraction wave on sound pressure and the particle velocity components in y axis is strong only on near field and high frequency, but for particle velocity component in x axis, on near field, the effect is always strong both at high and low frequency. The effect of diffraction wave can be ignored only in the far field for particle velocity component in x axis. The description of reference for influences on the directivity of vector sensor by soft ball boundary is not consistent with us.