含螺旋结构的水下声学覆盖层吸声特性研究OA北大核心CSTPCD

An underwater acoustic anechoic coating with a cylindrical cavity and a metal spiral structure was designed.The average sound absorption coefficient of this coating is above 0.85 in the frequency range of 565-5 000 Hz.This coating has the characteristics of broadband and high sound absorption capacity.The effect of the displacement variation characteristics of the coating and the structural geometric parameters on the sound absorption performance are analyzed by means of the finite element method.The results show that the introduction of the metal spiral structure can cause the reverse motion of the substrate rubber(opposite to the displacement direction of the substrate rubber caused by the incident wave),and the motions in the two directions can be canceled each other to a certain extent,which consumes the incident acoustic energy and effectively improves the sound absorption performance.The increase of blade width,cavity radius and spiral order can make the absorption peak shift to lower frequency side,but the overall absorption performance will be reduced.