Modeling an ocean pond. A two-dimensional, finite element hydrodynamic model of Ninigret Pond, Charlestown, Rhode Island. Technical report

The proposed site for a nuclear electric power station is on the north shore of Ninigret Pond in Rhode Island. The determination of the hydrodynamic characteristics of the salt pond is the preliminary step for subsequent investigations of parameters such as water quality, temperature, and sedimentation. Tidal motion in a shallow estuary has been modeled mathematically by vertically integrated, two-dimensional, hydrodynamic equations which present the approach to modeling in this work. But due to the complexity of this system of non-linear partial differential equations and the existence of irregular geometric boundary conditions in the pond, an analytical solution is not feasible. Instead, two numerical techniques, the finite difference and the finite element, usually are applied to real estuaries. This study used the Galerkin weighted-residual method through which the finite-element scheme can be implemented without a knowledge of the particular variational principle of the governing equation. The objectives of this report are: (1) To investigate the efficiency of different numerical integration schemes; and (2) to develop a suitable finite-element algorithm to simulate the tidal currents in Ninigret Pond