波浪中浮体运动的时域混合格林函数法

基于混合格林函数法,对浮体在波浪中的运动进行了时域模拟.通过假想的直壁控制面将流场分割成内域和外域,分别引入Rankine源和自由面格林函数并结合控制面上的连续条件,对初边值问题进行求解.利用开发的数值计算程序对圆柱形平台和S175船进行了计算分析,给出了时延函数、波浪力幅值和运动响应结果,通过与频域方法和试验数据对比,证明该方法对零航速和有航速水动力问题均适用,能有效解决外飘船型的数值发散问题,且具有更高的计算效率.

Hybrid Green Function Method for Time-Domain Analysis of Motions of Floating Body in Waves

A hybrid Green function method in time domain was applied for simulating the motions of floating body in waves. The fluid filed was decomposed into inner and outer domain by an imaginary control surface; the Rankine source method was applied in the inner domain while the transient Green function method was used in the outer domain. Two initial boundary value problems were solved by the continuity condition on control surface. The corresponding numerical codes were developed and the retard functions, wave exciting forces and motions in waves for a cylindrical platform and S175 containership were presented and verified. The comparison between numerical results, experimental data and frequency results were in good agreement, which shows that the present method is efficient and suitable for the hydrodynamic problem with or without forward speed. The good numerical stability is proved by solving divergence problem of ship with flare.