The Effect of Wave Non-Linearity on the Forces on a Wind Turbine Foundation in Shallow Water

摘要

A phase-averaging wave model (SWAN) is used to transform sea states in intermediate waters to the near-to-shore site of a wind-power plant. The supporting structure of the wind-power plant consists of a cylindrical monopile. The wave forces and resulting base moments on it are calculated by Morison's equation integrating from the bottom to the instantaneous free surface. For that purpose the wave-motion at the monopile is realised by a non-linear random wave model. Comparisons are made with a linear random wave model. The effect of the non-linear realisation on the variance of the surface elevation and the loads is studied. The relevance of using a non-linear realisation is discussed with respect to the effect on the calculated loads. The purpose of the study is to see how important it is to use a nonlinear approach when assessing wave loads in shallow water.