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Zero mass error using unsteady wetting–drying conditions in shallow flows over dry irregular topography
Author(s) -
Brufau P.,
GarcíaNavarro P.,
VázquezCendón M. E.
Publication year - 2004
Publication title -
international journal for numerical methods in fluids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 112
eISSN - 1097-0363
pISSN - 0271-2091
DOI - 10.1002/fld.729
Subject(s) - riemann solver , discretization , mechanics , finite volume method , wetting , shallow water equations , work (physics) , flow (mathematics) , computer simulation , polygon mesh , mathematics , solver , geometry , numerical analysis , conservation of mass , volume of fluid method , geology , mathematical analysis , physics , mathematical optimization , thermodynamics
A wetting–drying condition (WDC) for unsteady shallow water flow in two dimensions leading to zero numerical error in mass conservation is presented in this work. Some applications are shown which demonstrate the effectiveness of the WDC in flood propagation and dam break flows over real geometries. The WDC has been incorporated into a cell centred finite volume method based on Roe's approximate Riemann solver across the edges of both structured and unstructured meshes. Previous wetting–drying condition based on steady‐state conditions lead to numerical errors in unsteady cases over configurations with strong variations on bed slope. A modification of the wetting–drying condition including the normal velocity to the cell edge enables to achieve zero numerical errors. The complete numerical technique is described in this work including source terms discretization as a complete and efficient 2D river flow simulation tool. Comparisons of experimental and numerical results are shown for some of the applications. Copyright © 2004 John Wiley & Sons, Ltd.