A TURBULENCE-RESOLVING EULERIAN TWO-PHASE MODEL FOR SEDIMENT TRANSPORT

Abstract

A turbulence-resolving two-phase Eulerian model for sediment transport is developed by extending the new solver twoPhaseEulerSedFoam. The development and validation of a turbulence-averaged multi-dimensional two-phase model for sediment transport, twoPhaseEulerSedFoam version 1.0, was recently completed and the model was dissem- inated to the research community via the Community Surface Dynamics Modeling System (CSDMS) model repository. In order to resolve flow turbulence and turbulence-sediment interaction, large eddy simulation (LES) with subgrid tur- bulence closure is further implemented and simulation is carried out in three-dimension. Closures on particle stresses are based on kinetic theory of granular flow for binary collision and phenomenological closure for stresses of enduring contact. One of the main concerns in a turbulence-resolving simulation is regarding the domain size and finest grid resolution so that the flow domain is sufficiently large to contain the largest eddy and meanwhile, a significant amount of the turbulence energy is resolved appropriately. This paper discusses these crucial issues for typical sheet flow condition in oscillating water tunnels. Preliminary results also show that the model is able to capture the sediment burst events during the flow reversal.