利用互易定理的混响声场数值模拟

Numerical Simulation of Reverberant Acoustic Field Adopting Reciprocity Theorem

运用有限元-边界元耦合的数值模拟方法,对航天器结构在发射飞行阶段的高强度噪声环境激励响应问题进行了研究.首先介绍了传统的构建混响声场的数值模拟方法;其后利用声振耦合中的互易定理,将混响声场的激励问题转化为结构模型上力激励引起的场点声压响应问题,并采用随机分析原理,用谱分析方法推导了结构在混响声场激励下的响应计算公式;最后建立了航天器典型结构的声振耦合模型,并分别用传统方法和利用互易定理的方法进行了数值模拟.结果表明:2种方法的仿真结果几乎完全吻合,而且相对于传统方法,利用互易定理的数值模拟方法可以显著减少求解的时间和存储计算文件的空间.

Predicting noise-induced vibration from acoustic loads experienced in launch environment was investigated with the coupled finite element method and boundary element algorithm.The conventional numerical simulation of a reverberant field as a launch acoustic environment was introduced.Following the reciprocity theorem used in the coupled FE-BE model,the structural response due to reverberant acoustic excitation was substituted by the sound pressure caused by force excitation on the structure,then the output response power spectrum density of the coupled model subjected to reverberant environment was evaluated based on the stochastic analysis principle.To verify the accuracy and efficiency of the proposed method,it was used to simulate a force-excited structure.The simulation results were in good agreement with the solutions from the conventional methods.