Development of 3-D Fully Nonlinear Numerical Wave Tank to Simulate Floating Bodies Interacting with Water Waves

摘要

A Numerical Wave Tank (NWT) for 3-D problems is developed. The motion of an ideal fludi and the motion of a floating body are simulated in a time domain. The Boundary Value Problems (BVP) for velocity field and acceleration field are solved taking into account the interaction between the fluid and floating body motions. The Quadratic Boundary Element Method (QBEM) is used to solve these fields. Implicit boundary condition method is used for the acceleration field. Time integration is carried out with the 4th order Runge-Kutta method (RK4). Free surface is updated with the Semi-Lagrangian time marching scheme. A double-node technique is used to properly update the intersections between the free surface and the body. Some calculations are carried out by the newly developed 3-D NWT and the following three cases are presented in this paper. 1. The simulation of 3-D waves in a circular wave basin. 2. The simulation of hydrodynamic forces on a sphere in forced heave motion. 3. The simulation of the free heave motion of a sphere in a circular wave basin.