A curvilinear version of a quasi-3D nearshore circulation model

Abstract

A curvilinear version of the nearshore circulation model SHORECIRC is developed based on the quasi-3D nearshore circulation equations derived by Putrevu and Svendsen [Eur. J. Mech. 18 (1999) 409–427]. We use a generalized coordinate transformation and re-derive the equations in tensor-invariant forms. The contravariant component technique is used to simplify both the transformed equations and boundary conditions. A high-order finite-difference scheme with a staggered grid in the image domain is adopted for the numerical model. Very good convergence rates with both grid refinement and time refinement are obtained in a simple convergence test. The model is then applied to four cases involving either a non-orthogonal quadrilateral grid or a generalized curvilinear grid. The versatility of the curvilinear model in dealing with curved shorelines, nearshore breakwaters and other complicated geometries is demonstrated in the test cases. The accuracy of the model is shown in the paper through model/data comparisons in two of the case studies.