A BFG model for calculation of tidal current and diffusion of pollutants in nearshore areas

This study presents a boundary-fitted grid(BFG) numerical model with an aim to simulate the tidal currents and diffusion of pollutants in complicated nearshore areas.To suit the general model to any curvilinear grids,generalized 2-D shallow sea dynamic equations and the advection diffusion equation are derived in curvilinear coordinates,and the contravariant components of the velocity vector are adopted for easily realizing boundary conditions and making the equations conservational.As the generalized equations are not limited by a specific coordinate transformation,a self-adaptive grid generation method is then proposed conveniently to generate a boundary-fitted and varying spacing grid.The calculation in the Yangpu Bey and the Xinying Bey shows that this is an effective model for calculating tidal currents end diffusion of pollutants in the more complicated nearshore areas.