Boundary fitted grid models for tidal motions in Singapore coastal waters

This paper describes the application of a 2-D nested model in rectangular coordinates and an orthogonal boundary fitted grid (BFG) model to tidal motions in Singapore coastal waters. The basic mathematical model for shallow water waves in the BFG model is derived from the transformation of corresponding depthaveraged equations in rectangular coordinates. The curvilinear coordinate system is obtained from the solution of a grid generator based on the elliptic generation technique. The BFG model is applied to the Singapore coastal region and its surrounding waters with a complicated domain and internal island groups. The tidal flow behaviour including current circulation, time history of sea levels and currents as well as patterns of residual currents are investigated. The numerical results are successfully compared with the field measurements.