Author(s): Carlo Gualtieri; Petra Amparo Lopez Jimenez; Jesus Mora Rodriguez
Linked Author(s): Carlo Gualtieri, Jesús Mora Rodríguez
Keywords: Environmental hydraulics; Turbulence modelling; Dead zone geometry; Exchange processes; Experimental validation
Abstract: In rivers, dead zones can be due to geometrical irregularities in the riverbanks and riverbed and/or to spur dikes and groyne fields. Dead zones significantly affect mass transport, since contaminants are first trapped in the dead zone and later released back in the main stream due to transverse turbulent diffusion. This contribution presents the results of a comparison among the performances of some turbulence models applied to simulate fundamental flow phenomena and exchange processes in a simplified geometry, representing dead zones in natural rivers. Three commercial codes, Multiphysics 3.5™, Fluent 6.3™ and STAR-CCM+3.06™, were selected to carry out 2D steady-state numerical simulations in a geometry reproducing the case experimentally studied by Muto et al. in 2000. Simulated flow patterns generally agreed with those observed, whereas simulated exchange rates between the dead zone and the channel were in the range from 60% to150% of the experimental data.
Year: 2009