Slurry Transport in a Channel with TwoPhaseEulerFoam
CEDA Dredging Days 2019
T.D. Schouten, G.H. Keetels and C. van Rhee
Abstract: In dredging applications, deep sea mining and land reclamation projects typically large amounts of sediments are transported through pipes in the form of hyper concentrated (40% sediment or more) sediment-water mixtures or slurry. These slurry's can flow at three different regimes. 1: fully suspended (homogeneous and stratified) 2: partially suspended with a sliding bed 3: partially suspended with a fixed bed. At the moment it is hard to predict the transport regime, the volume flux of particles and the pressure drop (friction factor) of these slurry's within these regimes. The goal is to establish a model 3D continuum model that is able to predict the aforementioned aspects of slurry flow in a wide range of slurry flow conditions. In this paper it is investigated how well an existing CFD-model is able to model velocity and concentration profiles of suspended sediment in a uniform channel flow. The CFD-model that is used is TwoPhaseEulerFoam which is part of OpenFOAM. This Euler-Euler solver treats both the phases as an continuum with its own momentum and continuity equations. The phases are coupled with coupling terms such as the drag force. To investigate if the solver accounts for hindered settling effects correctly the solver is tested to several theories of hindered settling. After confirmation of the hindered settling the model is validated to experimental tests of low concentration channel flow experiments. The calculations give an excellent match for concentration and velocity.
Keywords: Slurry transport, channel flow, CFD, two-phase flow