The diffracted sound field from the transition region of an axisymmetric body in water  

作　　者：黎雪刚 杨坤德 汪勇 

机构地区：[1]College of Marine,Northwestern Polytechnical University

出　　处：《Chinese Physics B》2011年第7期243-251,共9页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundational of China (Grant No.10774119);the Program for New Century Excellent Talents in University of Ministry of Education of China (Grant No.NCET-08-0455);the Natural Science Foundation of Shaanxi Province of China (Grant No.SJ08F07);the Foundation of National Laboratory of Acoustics of China;the Foundation for Fundamental Research of Northwestern Polytechnical University of China (Grant No.2007004)

摘　　要：Understanding the physical features of the diffracted sound field on the surface of an axisymmetric body is important for predicting the self-noise of a sonar mounted on an underwater platform. The diffracted sound field from the transition region of an axisymmetric body was calculated by the geometrical theory of diffraction. The diffraction ray between the source point and the receiving point on the surface of an axisymmetric body was calculated by using the dynamic programming method. Based on the diffracted sound field, a simulation scheme for the noise correlation of the conformal array was presented. It was shown that the normalized pressure of the diffracted sound field from the transition region reduced with the increases of the frequency and the curvature of the ray. The flow noises of two models were compared and a rather optimum fore-body geometric shape was given. Furthermore, it was shown that the correlation of the flow noise in the low frequencies was stronger than that in the high frequencies. And the flow noise received by the acoustic array on the curved surface had a stronger correlation than that on the head plane at the designed center frequency, which is important for sonar system design.Understanding the physical features of the diffracted sound field on the surface of an axisymmetric body is important for predicting the self-noise of a sonar mounted on an underwater platform. The diffracted sound field from the transition region of an axisymmetric body was calculated by the geometrical theory of diffraction. The diffraction ray between the source point and the receiving point on the surface of an axisymmetric body was calculated by using the dynamic programming method. Based on the diffracted sound field, a simulation scheme for the noise correlation of the conformal array was presented. It was shown that the normalized pressure of the diffracted sound field from the transition region reduced with the increases of the frequency and the curvature of the ray. The flow noises of two models were compared and a rather optimum fore-body geometric shape was given. Furthermore, it was shown that the correlation of the flow noise in the low frequencies was stronger than that in the high frequencies. And the flow noise received by the acoustic array on the curved surface had a stronger correlation than that on the head plane at the designed center frequency, which is important for sonar system design.

关 键 词：diffracted sound field flow noise uniform geometric theory of diffraction CORRELATION 

分 类 号：O427.2[理学—声学]