Titre/Title : Numerical modelling of extreme hydrodynamics loads on offshore renewable energy concepts
Contact : Cyrille Bonamy
Résumé/Abstract :
Marine Renewable Energy (MRE) is a promising sector for sustainable low-carbon energy production. Despite the effort put in the last decade, concerning problems remained unsolved, in which the survivability appears as a principal lock limiting development.
This research - sponsored jointly by DNV GL and the University of Plymouth - aims to improve the numerical modelling of extreme Wave Structure Interaction (WSI) by coupling DNV-GL’s model, WaveDyn, with the Computational Fluid Dynamics (CFD) code OpenFOAM.
A CFD based Numerical Wave Tank (NWT) for extreme WSI is developed and validated against experiments performed at the University of Plymouth physical wave-tank, of a 100 year-return storm on a single moored Wave Energy Converter (WEC). CFD computational cost remaining too important for industries, the limit in the validity of the lower fidelity model, WaveDyn, is assessed against the experiments to characterise parametrically the range of use of each model. WaveDyn is coupled to the OpenFOAM-NWT by swapping between models as a function of the parameter identifying WaveDyn validity threshold. This strategy requires starting CFD from an advance time using the Rigid Body Motion (RBM) solution from WaveDyn, and a linear description of wave-group. The strategy is found to optimise the extreme modelling by reducing the use of CFD making the modelling of long irregular sea-state affordable for the coupled solver.