Dispersion, velocity measurements and secondary flow in coastal areas

DIEZ M; A RODRIGUEZ; REDONDO JM; J VILA

Vilanova

Conferencia; VIII INTERNATIONAL CONFERENCE ADVANCES IN TURBULENCE; 2005

ERCOFTAC UPC

A series of experimental measurements of the Lagrangian characteristics of the surfacecurrents in and near the Barcelona harbour have been performed during a two yearperiod for different wind and wave conditions. The seasonal influence on the waterrecirculation and the influence of tidal seiches is apparent when the formation of a localthermocline also forces strong vertical shear. The identification of stagnation points andthe role of the friction by the wind have to be taken into account in certain typicalconditions. Image analysis of both buoys and tracers help to identify the recirculatingareas and to estimate the flushing time in terms of different forcings outside the harbourarea. There are regions with parabolic or even smaller time dependence of the relativedispersion.