Multi-Directional Random Wave Transformation Model Based on Energy Balance Equation

The purpose of this paper is to develop a prediction model for multi-directional random wave transformation. The wave prediction model is based on an energy balance equation with an energy dissipation term and a newly formulated wave diffraction term from a parabolic approximation wave theory; the wave model is stable when solved numerically. The model calculations are carried out for three cases: the first case is the wave transformation through a gap between two breakwaters and the predictions axe compared with the solutions of the Sommerfeld diffraction theory; the second case is the wave deformation due to an elliptic shoal and the predictions are compared with the experimental observations; the third case is the transformation of swells propagating into the Osaka Bay through narrow channels. These model calculations showed that the proposed wave model gives reasonable predictions.