Sediment transport: continuous versus discrete model

摘要

In the present work a continuous model for fluid-particle flow computation is presented; the effects of particles &e taken into account in terms of an effective viscosity, whereas the dispersed phase equation closure is simply based on particles buoyancy. The proposed approach allows the study of sediment transport without the need of curvilinear co-ordinate Systems and the related step-by-step regridding, to describe accurately the evolution of bed forms. In fact in the present model the bottom shape is described in terms of a density contour line, rather then a moving boundary of the fluid domain. Numerical properties of discrete schemes for convective transport were carefully investigated by suitable test eases. The model has been validated in comparison with a Lagrangian approach, in the simple ease of settling particles in a Couette flow.