A parallel 2D finite volume scheme for solving the bilayer shallow-water system: modellization of water exchange at the Strait of Gibraltar

摘要

Two layer flows occur naturally in estuary flows, ocean currents, atmospheric flows, flows with different density pollutants, etc. This kind of flows are interesting from a theoretical and practical point of view. In this work, our interest focuses on the Strait of Gibraltar. In this narrows, connecting the Atlantic Ocean with the Mediterranean Sea, two layers of different waters can be distinguished: the colder and less saline Atlantic water flowing at surface and penetrating into the Mediterranean, and the deeper, denser Mediterranean water flowing into the Atlantic. In the first part of this work, a 2D two-layer shallow water system is presented together with an explicit edge-based finite volume numerical scheme developed by following the ideas described in [4]. Due to the size of the domain a parallel implementation based on OOMPI has been performed. The domain decomposition is carried out by using Chaco as a mesh partitioner integrated in the code. A special treatment of the open boundaries has been implemented in order to reduce the communication among processors. Finally, the numerical model has been applied to the simulation of the flow trough the Strait of Gibraltar with real bathimetric and coast-line data and measurements of the performance of the parallel implementation are presented.