Strato limite oscillante su una parete scabra

The oscillatory boundary layer originated by surface gravity waves of small amplitude over a rough bottom is investivated by means of a numerical approach. Results show that the flow differs from Stokes' solution within a boundary layer the thickness of which is of the same order of magnitude as the height of the roughness elements. In the latter layer the flow is strongly influenced by the vorticity shed from the roughness. When the height of the roughness elements is larger than the thickness of the Stokes boundary layer, it appears necessary to introduce a further flow regime which can be defined as "laminar rough regime".