Abstract
A numerical wave-absorption filter has been developed for open boundary condition in the analysis of nonlinear and irregular wave evolution. The filter is composed of a simulated sponge layer and Sommerfeld's radiation condition at the outer edge of the layer. The wave-absorption characteristics of the filter have been investigated by applying to the linear potential theory and to a two-dimensional nonlinear boundary element model. In both cases, the filter is found to be applicable for a wide range of wave parameters. In order to realize a practical ‘Numerical Wave Tank’, the present model also incorporates a wave generator in the computational domain composed of a series of vertically aligned point sources. Numerous numerical experiments demonstrate that the present approach is effective in generating arbitrary wave profile without reflection not only at the open boundaries but also at the wave generator.
