Influences of Cylindrical Carrier's Size and Shape of Undersurface on the Directivity of Vector Sensor

Guolong Liang ,Fubin Pang ,Guangpu Zhang

doi:10.19026/rjaset.7.232

Abstract

When the acoustic vector sensor is installed on underwater carrier to detect and position targets, the measuring results will be influenced by the diffraction of the carrier. Due to the differences of the sizes and shapes of the carrier, the influences of the diffraction on acoustic vector sensor are also different. Using BEM, the influences of cylinderâ€™s size and shape of undersurface on the directivity of acoustic vector sensor are calculated in this study. The results show that: the influences of diffraction on acoustic vector sensor are proportional to the length of cylinderâ€™s radius and height; besides, the sharper the undersurface is, the less influences acoustic vector sensor subjects to diffraction of the carrier. The experiment that carried out in the lake proves the validity of the computing. The research is effective guidance for the application of acoustic vector sensor.

Highlights

Composed by omni directional sound pressure sensor and dipole directional particle velocity sensor, acoustic vector sensors picks up both pressure and vibration velocity information in acoustic field, which expends the signal processing space and provides new thought and method for solving underwater acoustic problems (Sun and Li, 2004)
When it is installed on underwater carrier to detect and position targets, the diffraction of the carrier will distort the free space field, influencing the measuring results of vector sensor
The influences of cylindrical carrier’s sizes, shapes of undersurface on the directivity of acoustic vector sensor are studied and experiment was carried out to prove the validity of the calculation

Summary

INTRODUCTION

Composed by omni directional sound pressure sensor and dipole directional particle velocity sensor, acoustic vector sensors picks up both pressure and vibration velocity information in acoustic field, which expends the signal processing space and provides new thought and method for solving underwater acoustic problems (Sun and Li, 2004). When it is installed on underwater carrier to detect and position targets, the diffraction of the carrier will distort the free space field, influencing the measuring results of vector sensor. The pressure and velocity of acoustic diffraction field by infinite rigid spheroid have been calculated using MATLAB PDE toolbox and the method of calculating the diffraction of shell structure in any shape is proposed (Kang, 2002). The model of the diffraction by elastic shell with filler inside using BEM+FEM is built and the calculating results show that the diffraction of the filler will change the characteristics of acoustic field (Zhuo et al, 2009). The influences of cylindrical carrier’s sizes, shapes of undersurface on the directivity of acoustic vector sensor are studied and experiment was carried out to prove the validity of the calculation

THEORY OF DIFFRACTION CALCULATION USING BEM

SIMULATION AND ANALYSIS

EXPERIMENTAL RESULTS AND ANALYSIS