Author(s): Behnam Shabani; Abbas Yeganeh; Sam S. Y. Wang
Linked Author(s):
Keywords: Euler-lagrange coupling; Two-phase flow; Sheet flow; Granular material; Movable Bed Simulator 3D (MBS-3D); DEM
Abstract: A two-phase flow model, namely MBS-3D, is presented for the simulation of bed-load transport in three-dimensional coordinates with focusing on characteristics of movable bed layer. The model is constructed with Euler-Lagrange coupling of fluid and sediment phases, respectively. The flow phase is computed as unidirectional flow condition with assuming a logarithmic velocity distribution over flow depth with adding the turbulent component intensities in three dimensions. The sediment transport is described as the motion of a granular media under the action of a steady flow, based on the Distinct Element Method (DEM), with accounting for interparticle collision of the moving bed particles. The characteristics of mean-flow velocity and concentration of bed-load are discussed, at different rate from low to high bed shear stress, by the present model. In addition, the characteristics of mean velocity as well as concentration profiles of sediment phase is studied and discussed in light of the interphase momentum transfer. Finally, the transport rate resulted from the model has been compared with both the result of a two-dimensional model of MBS-2D model and the Meyer-peter Muller formula of bed-load transport. Comparison shows that the MBS-3D model provides a better agreement with the conventional bed-load formula, especially at higher bed shear stresses.
Year: 2005