A 2DH IMPLICIT MODEL TO NUMERICALLY STUDY HYDRODYNAMICS AND SEDIMENT TRANSPORT TRENDS OF A REAL SHALLOW TIDAL EMBAYMENT: THE ARCACHON LAGOON (FRANCE)

摘要

In the present study, a new numerical model is proposed, devoted to the simulation of the shallow coastal flows in tidal bays, capable to tackle with difficulties arising from varying bottom, wetting and drying processes as well as large time step simulation with reasonable computing time cost. For numerical treatment of dry zones emerging during wetting and drying processes, a Darcy type tenm is addeding in the classical SWE and a penalty method is employed. Governing equations are discrstized using an implicit Finite Volume approach on a staggered grid. An adaptation of the augmented Lagrangian method is used for resolution of water depth and current fields. The present numerical modeling is validated by comparison with several literature test cases from the literature before being applied to a real tidal embayment. The application of the model to the Arcachon lagoon allows to highlight some trends on tidal circulation and possible sediment transport in the lagoon, where the alternative dominance of the study of the hydrodynamics and the consecutive sediment transport trends that occur in a real tidal bay: the Arcachon lagoon.