Coupling HPC and Numerical Validation: Accurate and Efficient Simulation of Large-scale Hydrodynamic Events

This paper highlights the HPC capabilities of TELEMAC-2D, a Finite Element shallow water equation code developed by EDF R&D. A demonstration test case using a 12-million element grid is presented of the flow in the Gironde Estuary in southwest France. Preliminary tests are performed to study round-off error propagation which might be amplified when running HPC simulations. The original mesh of the estuary containing approximately 0.2 million elements is successively refined by splitting each triangular element into four sub-elements to obtain meshes containing 0.8, 3 and 12 million elements, respectively. The paper details the scaling performance of the code and also shows that the predicted free surface elevation within the estuary is affected by the mesh resolution.