2022 Volume 78 Issue 2 Pages I_397-I_402
To calculate the wave forces acting on the monopiles for offshore wind turbines, two methods are available: one is the method using the numerical wave flume, CADMAS-SURF, which compute nonlinear wave field as a direct solution of fluid dynamics. The other is the constrained wave method which is based on a linear irregular wave train in which a finite amplitude wave solution is embedded in the maximum wave. This study focuses on the applicability of the two methods in the calculation of the wave force by Morrison equation which calculates the drag and inertia from the water particle velocity and acceleration. From the computations of two depth conditions, 10m and 40m, the followings are made clear: 1) Since the waves in the deep water can be assumed mostly linear, the constrained wave method, which has a smaller calculation load than CADMAS-SURF, is more reasonable for computations of deep irregular wave motions. 2) In shallow water where wave breaking and wave nonlinearity are dominant, the analysis of nonlinear irregular wave fields by CADMAS-SURF with appropriate grid resolution is desirable.
