An implicit three-dimensional numerical model to simulate transport processes in coastal water bodies

A three-dimensional baroclinic numerical model has been developed to comput e water levels and water particle velocity distributions in coastal waters. The numerical model consists of hydrodynamic, transport and turbulence mod el components. In the hydrodynamic model component, the Navier-Stokes equat ions are solved with the hydrostatic pressure distribution assumption and t he Boussinesq approximation. The transport model component consists of the pollutant transport model and the water temperature and salinity transport models. In this component, the three-dimensional convective diffusion equat ions are solved for each of the three quantities. In the turbulence model, a two-equation k-is an element of formulation is solved to calculate the ki netic energy of the turbulence and its rate of dissipation, which provides the variable vertical turbulent eddy viscosity. Horizontal eddy viscosities can be simulated by the Smagorinsky algebraic sub grid scale turbulence mo del. The solution method is a composite finite difference-finite element me thod. In the horizontal plane, finite difference approximations, and in the vertical plane, finite element shape functions are used. The governing equ ations are solved implicitly in the Cartesian co-ordinate system. The horiz ontal mesh sizes can be variable. To increase the vertical resolution, grid clustering can be applied. In the treatment of coastal land boundaries, th e flooding and drying processes can be considered. The developed numerical model predictions are compared with the analytical solutions of the steady wind driven circulatory flow in a closed basin and of the uni-nodal standin g oscillation. Furthermore, model predictions are verified by the experimen ts performed on the wind driven turbulent flow of an homogeneous fluid and by the hydraulic model studies conducted on the forced flushing of marinas in enclosed seas. Copyright (C) 2000 John Wiley & Sons, Ltd.