平头物体三维带空泡入水的数值模拟

NUMERICAL SIMULATION OF 3-D WATER ENTRY OF BLUNT CYLINDER WITH A VENTILATEDCAVITY

本文用时间步进法和边界积分方程方法数值求解平头物体的垂直及斜向入水过程,这是一个在非线性自由面条件下,物体与流体有耦合作用,三维、非定常、理想不可压流体的运动问题,自由面用Lagrangian参数描述,物面用固结在物体上的Eulerian坐标描述,数值计算上提出了物面动力学条件(流-固耦合运动方程)和自由面动力学条件的二阶精度的时间差分隐格式,最后给出若干入水情况的详细计算结果。

A method is developed in which the time-stepping algorithm and the boundary integral equation method are employed to calculate vertical and oblique water entry of a blunt cylinder, which is a 3-d, nonsteady, incompressible and inviscid fluid flow problem with nonlinear free surface and fluid-body interaction. The free surface is described in terms of La-grangian coordinates and the body surface is described in terms of Eulerian coordinates fixed in the body. Implicit schemes of second-order precision time-difference of free surface condition and body surface condition are constructed and used. Computational results of a number of cases of water entry are presented in details.