Experiments and Model Equations for Generating Waves on Top of Currents

This paper deals with experiments and theoretical models for wave-current interaction in hydrodynamic laboratories. Different from ocean-engineering applications, the laboratory situation corresponds to a closed system. A model is proposed to compare wave-only and current-only quantities with properties of the waves and current in interaction. The model is based on conservation of mass-trans port and energy-flux, and is an extension of other models known in literature. We compare the various models with experiments; for regular waves we exploit the experimental results of Thomas ([9]), while for irregular waves we report and use experiments performed at MARIN. The proposed model performs best of all models when both cases are considered. But for irregular waves the simpler model that takes for the energy-flux the product of group velocity with energy performs even better. More experimental results would be needed to improve and justify the theoretical models.