Study on Numerical Simulation of Three-dimensional Multi-directional Freak Waves Based on OpenFOAM

Abstract

A three-dimensional numerical model was built by developing the standard solver interFoam in the open source CFD toolbox OpenFOAM. In the developed interFoam, a three-dimensional wavemaker boundary condition based on directional spectra and absorbing boundary conditions are added. The numerical model had been used to simulate multi-directional freak waves. The performance proof of the numerical model was carried out by comparing the numerical results with experiments and target spectra. And then Effects of grid interval and maximum courant number on multi-directional freak wave simulation are analyzed. The freak wave groupiness are examined and compared by the conventional run length approach and smoothed instantaneous wave energy history approach. The following conclusions are drawed. The satisfactory multi-directional freak waves result on the condition of the grid resolution of 0.02m0.01m0.02m and the courant number of 0.25. The energy approach is more appropriate for freak wave groupiness description.