Parlons Sciences

Visit from Alexandre CABOUSSAT, Professeur HES associé, HES-SO, Genève, Suisse.

Numerical simulation of free surface flows with sediment dynamics

We present a numerical model based on a mixture model for multiphase flows.

The Navier-Stokes equations for incompressible flow are coupled with the dynamics of the particles’ concentration (transport, deposition and resuspension), and a volume-of-fluid approach for the tracking of the free surface between water and air. The numerical algorithm relies on an operator-splitting method that decouples diffusion, advection and sedimentation processes. A two-grid method is used for the space discretization. A well-chosen mix of finite elements, finite volumes and characteristics methods are dedicated to each sub-step of the time evolution algorithm. The numerical model is validated through comparisons with 3D numerical experiments, focusing on sediment flushing, shear flow erosion, and dunes formation.