Open AccessWaves plus currents crossing at a right angle: Experimental investigation
Author(s) -
Musumeci R. E.,
Cavallaro L.,
Foti E.,
Scandura P.,
Blondeaux P.
Publication year - 2006
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2005jc002933
Subject(s) - current (fluid) , mechanics , superposition principle , perpendicular , surface finish , laminar flow , turbulence , flow (mathematics) , boundary layer , geology , optics , physics , geometry , materials science , oceanography , mathematics , quantum mechanics , composite material
The hydrodynamics generated by a regular wave field perpendicularly superimposed to a steady current is investigated by means of laboratory experiments. The flow structure is analyzed by measuring the velocity profiles using a micro Acoustic Doppler Velocimeter. Three cases are considered: current only, waves only and waves plus current. Different bottom roughnesses are used, and the apparent roughness k s is estimated for each condition. In the presence of a small roughness, the superposition of the waves on the current causes an increase of the current velocities close to the bottom, thus generating a decrease of the apparent roughness with respect to the case of the current only. On the other hand, when a large bottom roughness is present, the waves force a decrease of the current velocity close to the bottom and, in turn, an increase of the apparent bottom roughness. Such a behavior seems related not only to the roughness but also to the flow regime (i.e., laminar or turbulent) within the wave bottom boundary layer.