边界元计算内外声场耦合及流体目标声散射

为研究水下目标的耦合声散射问题，将声类比边界元技术应用于内声场、并考虑流体目标内外声场的耦合，建立了水下运动流体目标声散射的物理模型和数值方法．对于长圆柱和旋转椭球外型的流体目标，给出了几组声散射数值仿真结果，并和解析方法（变形圆柱法）的结果进行比较；比较结果的一致验证了该方法的正确性和有效性．该方法能够研究任意声波入射条件下复杂外形运动流体目标内外声场的耦合，结合结构的有限元描述，该方法将用于水下弹性结构的声耦合响应分析．

Coupling of exterior/interior field with BEM and numerical simulation of acoustic scattering of fluid target

With the coupling of exterior and interior sound field,the boundary element method(BEM) of acoustic analogy was expanded to include the scattering by fluid body underwater.The new method was verified by some numerical experiments of the scattering by the elongated cylinder and the prolate spheroid.The numerical results in different situations were coincident with those from an analytical approach named as deformed cylinder methods(DCM),which illustrated that the new method was reasonable and valid.The approach is valuable and useful for its capability to consider the movement effects of body with complex shape and its capability to involve the situation that the incident wave is in arbitrary direction;with FEM of structure,it can be used to analyze response of elastic structure underwater.