内部声激励下加筋圆柱壳的声辐射特性分析

SOUND RADIATION ANALYSIS OF STIFFENED CYLINDRICAL SHELLS EXCITED BY INTERIOR SOUND EXCIFATION

从Flügge薄壳理论和Helmholtz波动方程出发,根据模态叠加原理推导了有限长加筋圆柱壳受机械力和内部声源简谐激励下的"内部声腔-加筋柱壳-外部声场"耦合方程.比较了点力和点声源作用时圆柱壳的声辐射特性以及传递损失.结果表明:在讨论的频率范围内,点声源对内场均方声压起主要作用;点声源作用下外场辐射声压分布较均匀,其传递损失较点力作用下的大,但壳体的外场声辐射效率较点声源作用下的高.分析结果对圆柱壳体结构的声学设计具有一定的参考价值.

A ‘cavity-stiffened cylindrical shell-out radiated sound field ＇ coupling equation is presented based on Fltigge thin shell theory, Helmholtz equation on wave motion and the modal superposition principle. The paper evaluates the sound radiation characteristics and transmission loss of a submerged stiffened cylindrical shell excited by a harmonious point forces and an interior point source. After solving the cou- pling equation, comparison of underwater sound radiation properties of both exciting force and sound source is carried out. It is shown. 1） the inside radial quadratic pressure is primarily influenced by interior sources; 2） the outside sound pressure directivity of shells brought by sound source is weaker; 3） the transmission loss of sound source is larger than that by point force, but the radiation efficiency of the former is higher. The study is valuable for acoustic design of stiffened shells.