考虑水弹性影响的水下航行体结构动响应研究

考虑水弹性的影响，计及惯性力、水动力和弹性力之间的相互耦合作用，将水动力学方程和结构动力学方程联合求解，采用三维势流理论和边界元法推导并计算了水下航行体结构的附加质量矩阵，对带空泡水下航行体出水过程中的结构动响应问题进行了分析. 

DYNAMIC RESPONSE RESEARCH OF UNDERWATER VEHICLE WITH CONSIDERATION OF HYDROELASCITY

Cavitation occurs on the surface of the underwater vehicle in its high-speed motion. For reasons of cavity re-entry, cavity collapse, flows and waves, the fluid excitations of the vehicle are very complicated to induce transient responses in structures. Such responses will change the flow field around the structures thereby. Such an interaction represents the coupling phenomenon between fluid and structures in inertia, damping and elasticity. It is very hard to solve the fluid-solid coupling problem like that. The key of hydroelasticity is to consider the interaction in inertia, damping and elasticity forces and to solve the hydrodynamic and structural dynamic equations together. In recent years, many scholars have done a lot of work and solved many theoretical and engineering problems. In this paper, the added mass matrix, in which the interactions are taken into account in the structural dynamic equations under the influence of hydroelasticity, is obtained based on three-dimensional potential theory and Boundary Element Method (BEM). Consequently, the exiting-water dynamic response of the underwater vehicle with cavities is analyzed. The experimental and analytical results have shown that the cavity collapse produces strong dynamic responses in structures. The wet frequency of the vehicle changes with the cavity length. The system constructed by the fluid and the structures is time-dependent. The influence of hydroelasticity on the structural dynamic response can not be negligible. The structural frequency and the response amplitude in water have obvious differences compared with those in air due to hydroelasticity. The present scheme to solve the fluid-solid coupling problem has important significance in engineering applications.