Abstract
A full-nonlinear computation technique based on the Mixed Eulerian-Lagrangian method is presented and validated quantitatively for a fundamental 2-D radiation problem. The time marching is performed with the 4-th order Runge-Kutta-Gill algorithm, and at each time step the integral equations for the velocity and acceleration fields are solved by applying a higher-order boundary-element method with quadratic isoparametric elements. Stable simulations over a large number of periods are possible, because an efficient absorbing beach is used to avoid wave reflections from an outer boundary and regridding is performed to avoid the cluster of nodal points on the free surface.
Computed results are compared with linear-theory results of the Green function method in the time and frequency domains, measurements of the time history of waves generated by a wavemaker, and Fourier-analyzed results of hydrodynamic forces acting on an ellipse and a wedge. All of these results are in excellent agreement, confirming the validity of the calculation method.
