Hydrodynamics of wave forces on coastal-bridge decks: Calculations by Euler´s equations versus nonlinear shallow-water wave equations

Wave forces on coastal-bridge decks are calculated by Euler´s equations, and by nonlinear shallow-water wave equations. Euler´s equations are solved by use of an open source Computational Fluid Dynamics (CFD) software, namely OpenFOAM. In the numerical wave tank, Euler´s equations are solved for both water and air above, and the free-surface is determined by a Volume of Fluid interface tracking method. The wave forces are also calculated by the Level I Green-Naghdi nonlinear shallow-water wave equations, specifically developed for the problem of wave interaction with submerged bridge decks. The two methods are used in calculating solitary and cnoidal wave forces on submerged bridge decks (model and prototype) and results are compared with one another, and with the existing laboratory experiments. Discussion on accuracy, applicability and computational cost of these methods, under different physical conditions, is provided.