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Accueil du site > Évènements > Séminaires > Séminaires IRPHE > Archives IRPHE > 2017

Vendredi 3 Mars 2017 / IRPHE

publié le , mis à jour le

Séminaire régulier IRPHE

Numerical and experimental studies of nonlinear effects on surface and internal waves



Orateur : Jeffrey Harris
Saint Venan Laboratory for Hydraulics, ENPC, Paris

Résumé : Although linear wave theory is often needed for understanding waves in the ocean, for many important practical applications we find strong nonlinear effects. Here we present two types of applications :

With numerical modeling with the boundary element method of wave-structure interaction in the time domain, comparing with published experimental data for vertical cylinders (i.e. monopiles) or more complex surface-piercing structures offshore wind turbines, we are able to get good agreement for both the linear as well as the higher-order harmonic forces. By using such a fully nonlinear potential (i.e. inviscid) flow model, and seeing a difference in certain conditions, we also are able to identify cases where viscous effects might be important.

We similarly see highly nonlinear effects in previously unreported internal solitary waves in Port Susan, Puget Sound, a small estuary on the west coast of the United States. Although direct measurements of the generation and dissipation mechanisms have not yet been possible, the first known direct measurements of the wave propagation compare favorably with higher-order KdV theory, and the timing of the waves suggest that they are created by an interaction between the thin surface layer and the local bathymetry, driven by the tide. The resulting waves appear to be possibly a source of significant mixing in the calm basin. Due to the length- and time-scales involved, 3D modeling of the waves remains computationally difficult.

Date et Lieu : le Vendredi 3 Mars 2017 à 11h00, salle de séminaire IRPHE