非线性波流场和波流载荷的数值模拟

THE NUMERICAL SIMULATIONS OF WAVE-CURRENT FIELDS AND WAVE-CURRENT LOADS ON A LARGE CYLINDER

本文用数值模拟的方法研究了大尺度物体上所受的非线性波与水流的共同作用力。非线性水波与水流相互作用场的计算采用有限差分法,引入坐标变换获得了固定计算域,用松弛迭代法求解差分方程。波流联合作用力的计算用时间步进法,每一时刻采用简单格林函数的边界元法求解。入射势采用以上波流场的计算结果,开边界选取离物体足够远,其上的速度势为入射势。

In this paper, the numerical simulations of the nonlinear interaction of waves and currents and the loads excited by wave-current on a large cylinder are carried out.The finite difference method is used for discreting the equations which describe the two-dimensional, nonlinear waves and currents iuter-action problems. A transformation of coordinates is used in order to get a fixed calculation field. The difference equatiors are solved by an iterative method at each time step.The combined force of wave-ourrent is obtained by time-stepping method in which at each time step the velocity potential is calculated by an intergral equation based on Green's theorem. The rcident velocity potential is obtained by the upper numerical method of wave-current field. The open boundary is located far enough from the cylinder, then the incident velocity potential can be used as a open boundary condition.