Estimation of Wave Drift Force By Numerical Wave Tank

A fully nonlinear numerical wave tank (NWT) is applied to estimation of the wave drift force acting on two-dimensional fixed and floating bodies. This is a time domain simulation program which solves simultaneous equations of ideal fluid motion and floating body motion. Using this NWT, the diffraction problem and the radiation-diffraction problem of a two-dimensional Lewis form body in regular waves are simulated and the wave drift force is calculated both from transmitted wave and from direct pressure integral on the wetted body surface. To examine the accuracy of NWT, the first harmonic components of simulated hydrodynamic forces, body motions, wave reflection and transmission coefficients and wave drift force are compared with linear theory and experimental data of Nojiri (1975). The first harmonic components of the nonlinear simulation are confirmed to be in good agreement with linear theory.