Study of Viscous Effects on Wave Drift Forces on a Rectangular Pontoon With a Damping Plate by Using CFD Code OpenFOAM

Wave drift loads play a key role in station-keeping analysis of floating offshore structures. However, conventional radiation/diffraction tools have some limitations especially when the structure has sharp edges, requiring more extended validation. In this paper, a series of CFD computations are performed on a 2D simplified shape representing a rectangular-pontoon, with or without a horizontal damping plate. In the present study, the structure is considered to be fixed (radiation effects are not included). For validation, the results of CFD are compared with the results of experiments. The model tests are performed at the wave canal with an equivalent configuration. The drift forces are derived from the reflected and transmitted waves thanks to far field formulation. The incident, reflected and transmitted waves are separated by using a multi “sensors” method. The dissipation of wave energy is also investigated. The analysis is performed on two different model configurations: with and without the presence of a bottom damping plate. The effect of the damping plate on the wave energy dissipation and drift forces are discussed. The results obtained allows for a better understanding and will allow the study on more complex configurations.