规则迎浪中船舶参数横摇的三维时域预报方法研究

参数横摇是船舶因复原特性改变而引起的典型非线性现象。文章采用三维时域方法预报规则迎浪中船舶的参数横摇运动。该方法引入匹配面将流域分为内域和外域，内域中采用Rankine源来满足物面条件和线性自由面条件，而外域中应用时域格林函数来满足线性自由面条件和远场辐射条件。数值方法中，Froude-Krylov力和恢复力是通过对船舶瞬时湿表面积积分获得，同时考虑了横摇、垂荡和纵摇三自由度之间的耦合作用，以及非线性横摇阻尼的影响。数值结果与试验结果吻合很好，说明该方法可以有效地预报参数横摇。

Study on a 3D Time-domain Method to Predict Parametric Rolling of a Ship in Regular Head Seas

Parametric rolling is a nonlinear phenomenon due to roll restoring variation. A three-di-mensional (3D) time-domain method is used to predict parametric rolling of a ship in regular head seas. In this method, a matching surface around a ship is used to divide fluid domain into an inner domain and an outer domain. In the inner domain, the Rankine source is used to satisfy body bound-ary condition and linearized free surface boundary condition, while in the outer domain, the time-do-main Green function is applied to meet linearized free surface boundary condition and the far field radiation condition. Froude-Krylov forces and hydrostatic restoring forces are calculated by integrat-ing pressure under the incident wave surface. And the coupling of roll, heave and pitch, and nonlin-ear roll damping are considered. The numerical results are in good agreement with existing experi-mental results, which show that it is an efficient method for predicting parametric rolling.