Modeling of the near-field distribution of pollutants coming from a ă coastal outfall
Résumé
The present study concerns the 3-D distribution of pollutants emitted ă from a coastal outfall in the presence of strong sea currents. The ă problem is solved using the nonlinear Reynolds-averaged Navier-Stokes ă equations in the framework of the k-epsilon model. The constants of the ă logarithmic law for the vertical velocity profile in the bottom boundary ă layer are obtained by processing experimental data from acoustic Doppler ă current profilers (ADCPs). The near-field distribution of pollutants at ă different distances from the diffuser is obtained in terms of the ă ambient flow velocity (steady or with tidal effect) and outfall ă discharge characteristics. It is shown that even in the case where the ă effluent density is substantially lower than the ambient sea water ă density the plume can impact the seabed, creating a risk of pollution of ă removable bottom sediments.