Numerical Simulation of Wave Slamming on a Flap Type Oscillating Wave Energy Device

摘要

This paper presents the numerical investigations of an oscillating flaptypewave surge converter device operating in extreme sea states. Weuse the open-source CFD library OpenFOAM to carry out the twodimensionalnumerical simulations. A preliminary study is done toverify the convergence of our results while scalability tests confirm thehigh-performance computing capabilities of OpenFOAM and thepossibility to extend this study to large three-dimensionalconfigurations. The Oyster flap-type device is simulated with bothincompressible and compressible solvers and results are comparedagainst previous numerical and experimental results. It is shown thatan incompressible solver can capture well the dynamics and generalbehavior of the flap device. Nevertheless, the slamming eventscaptured in the laboratory can only be reproduced with the aid of acompressible solver, which takes into account density changes in the airand water phases. The numerically captured slamming events only takeplace if there is a preliminary formation of trapped air pockets on theseaward side of the flap. The entrapped air is subject to furthercompression and expansion thus confirming the importance ofcompressibility and aeration effects in agreement with thoughts basedon past experiments and numerical simulations.