Boundary-fitted non-linear dispersive wave model for regions of arbitrary geometry

A vertically integrated non-linear dispersive wave model is expressed in non-orthogonal curvilinear coordinate system for simulating shallow or deep water wave motions in regions of arbitrary geometry. Both dependent and independent variables are transformed so that an irregular physical domain is converted into a rectangular computational domain with contravariant velocities. Thus, the wall condition for enclosures surrounding a typical physical domain, such as a channel, port or harbor, is satisfied accurately and easily. The numerical scheme is based on staggered grid finite-difference approximations, which result in implicit formulations for the momentum equations and semi-explicit formulation for the continuity equation. Test cases of linear wave propagation in converging, diverging and circular channels are performed to check the reliability of model simulations against the analytical solutions. Cnoidal waves of different steepness values in a circular channel are also considered as examples to non-linear wave propagation within curved walls. In closing, remarks concerning versatility and practical uses of the numerical model are made.