Numerical simulation of extreme free surface waves

The generation of waves close to the breaking point was studied using two commercial software packages. These may be used to generate an extreme design wave to investigate the survivability of offshore wave energy converters or other devices operating in such a challenging environment. Regular and focused wave results were presented and compared with physical experiments and potential flow calculations. Three different focused wave groups were simulated using first and second order accuracy for the wavemaker signal. The damping of the wave in the numerical wave tank is likely to be caused partly by the fluid viscosity and partly due to numerical damping. A higher order time-Stepping scheme may reduce the level of damping. Different turbulence models and their effect on the level of damping in the numerical wave tank will be investigated in the next stages of the study. This is an abstract of a paper presented at the 18th International Offshore and Polar Engineering Conference (Vancouver, BC, Canada, 7/6-11/2008).