A comparison of wave generation methods simulating extreme waves in a numerical wave tank

Abstract

Extreme wave conditions emanate from the random and instantaneous interaction of waves during storm events. These wave conditions may cause potentially severe damage to ships and offshore oil and gas structures. There are several reported methods for simulating extreme waves. The main purpose of the present study is to simulate extreme waves with two different wave generation methods using the open-source CFD model REEF3D. Two extreme wave generation methods are considered: a focused wave group and an approach based on transient wave packets. The numerical model uses the incompressible Reynolds-Averaged Navier-Stokes (RANS) equations to model the two-phase flow. The free surface is represented with the level set method. A Dirichlet boundary condition is imposed at the inlet of the wave tank. Focused waves are generated by superpositioning of the linear wave components of an irregular sea state at an intended point in space and time. Whereas in the case of the transient wave packets, a large wave is generated at a certain concentration point along the tank by superimposing the wave components of the transient wave train. Further, the temporal and spatial development of extreme waves based on two methods are examined in the numerical wave tank.