An unstructured grid, three-dimensional model based on the shallow water equations
Article first published online: 31 JAN 2000
Copyright © John Wiley & Sons, Ltd.
International Journal for Numerical Methods in Fluids
Volume 32, Issue 3, pages 331–348, 15 February 2000
How to Cite
Casulli, V. and Walters, R. A. (2000), An unstructured grid, three-dimensional model based on the shallow water equations. Int. J. Numer. Meth. Fluids, 32: 331–348. doi: 10.1002/(SICI)1097-0363(20000215)32:3<331::AID-FLD941>3.0.CO;2-C
- Issue published online: 31 JAN 2000
- Article first published online: 31 JAN 2000
- Manuscript Revised: JAN 1999
- Manuscript Received: SEP 1998
- finite difference;
- finite volume;
- shallow water;
- unstructured grid
A semi-implicit finite difference model based on the three-dimensional shallow water equations is modified to use unstructured grids. There are obvious advantages in using unstructured grids in problems with a complicated geometry. In this development, the concept of unstructured orthogonal grids is introduced and applied to this model. The governing differential equations are discretized by means of a semi-implicit algorithm that is robust, stable and very efficient. The resulting model is relatively simple, conserves mass, can fit complicated boundaries and yet is sufficiently flexible to permit local mesh refinements in areas of interest. Moreover, the simulation of the flooding and drying is included in a natural and straightforward manner. These features are illustrated by a test case for studies of convergence rates and by examples of flooding on a river plain and flow in a shallow estuary. Copyright © 2000 John Wiley & Sons, Ltd.