Hybrid Physical-Numerical Modelling of Following Wave-Current Interaction

Abstract Both physical and numerical models face significant challenges in accurately replicating real-world wave and current conditions. Hybrid physical - numerical modelling enhances understanding of the limitations of selected setups. This study compares the effect of a following current on the evolution of regular waves in a physical and numerical wave-current flume. A following current stretches waves, increasing wavelength and decreasing amplitude. Wavemaker theories do not account for currents, complicating the calibration of wavemaker motion to achieve desired wave conditions at specific locations. Adopting a hybrid physical – numerical modelling approach within an experimental facility can potentially reduce the amount of iterations required for this calibration. The High-Order Spectral – Numerical Wave Tank (HOS-NWT) is modified to include the effect of a stationary current on the wave evolution. Good agreement with theoretical values is found. The numerical results are compared to physical measurements with both waves and currents in a confined section of the Coastal & Ocean Basin (COB) in Ostend, Belgium. For some of the considered conditions, turbulence-induced wave damping seems to occur in the experiments. This damping is not captured by the numerical model. Nevertheless, the results of these preliminary tests to verify the chosen methodology for modeling wave-current interactions are promising.