Multiphysics and multiscale coupling for wave height modelling in Le Havre harbor.
Résumé
A sensitivity study is performed to investigate the importance of multiphysics and multiscale couplings for modelling wave height in the outer Seine estuary (English Channel), the harbour of Le Havre and its new infrastructures Port 2000. Multiphysics coupling focuses on the effects of the tide in terms of time-varying water depths and currents on wind-generated surface-gravity waves. Simulations are based on the coupling of phase-averaged wave-propagation modules with circulation modules. This coupling is evaluated by comparing numerical results of the significant wave height with field data collected in November 2008 at two wave buoys moored in the access channel to Le Havre harbour. Predictions confirm a periodic local increase reaching 30 % of the wave height induced by current refraction. Multiscale coupling focuses on the importance of nested computational domains for predicting wave heights in the inner basin of Port 2000. A phase-resolving wave module is set up at this ultimate scale. Need of coupling this module with simulations at the scale of the outer Seine estuary is evaluated by comparing wave-agitation modellings driven by spatially-uniform and spatially-varying forcings with measurements in the inner basin. This comparison highlights the sensitivity of predictions to the directions of waves approaching the harbour entrance.