NUMERICAL AIMULATION OF WAVE IMPACT LOAD ON HIGH SPEED SHIPS

本文提出了一种计算任意形状物体水冲击的方法。采用拟体坐标系对刚体表面的任意轮廓进行建模，采用分数体积法求解自由表面的瞬态变形。这种数值技术的结合使刚性表面和自由表面的边界条件在两者的交点处得到了自然的处理，大大提高了数值模拟的稳定性和精度。为了验证这种计算方法，研究了楔形和圆柱体水冲击的经典问题。此外，还对实际船首截面的水冲击进行了模拟，以说明该计算方法对实际船舶设计问题的适用性。在这些基础研究中，我们考虑了身体以恒定速度进入最初平静的水面的情况。模拟结果与现有的分析理论和已发表的实验数据进行了比较。本文还对数值波浪产生技术进行了研究，为今后研究高速船舶在现实海上的撞击问题提供了理论依据。

In this study, a computing method for water impact of arbitrary shaped bodies is proposed. We use body-fitted coordinate system to model the arbitrary profile of the rigid body surface and the transient deformation of the free surface is solved by the fractional volume of fluid method. With this combination of the numerical techniques the rigid surface and the free surface boundary conditions are naturally treated at the intersection of both surfaces that improves remarkably the stability and accuracy of the numerical simulation.For the purpose of verifying the present computing method, classical problems of water impact of wedges and circular cylinders are studied. Moreover, water impacts of actual ship bow sections are simulated to illustrate the applicability of the present computing method to practical ship design problems. In these basic studies, we considered the cases in which the body enters an initially calm water surface with a constant velocity. The results of the simulations are examined against the existing analytical theories and published experimental data.Numerical wave generation technique is also studied for future research on the slamming of high speed vessels in realistic sea ways.