Author(s)

R. W. Barber, A. Fonty

Abstract

Numerical simulation of confined laminar flow over a backward-facing step using a novel viscous-splitting vortex algorithm R.W Barber', A. Font/ 'Centre for Microfluidics, Department of Computational Science and Engineering, Daresbury Laboratory, U.K. ~Lo\ver Base Engine Design Service, Renault, France Abstract A novel two-dimensional discrete vortex model is described for predicting low Reynolds number laminar flow behind a backward-facing step. The numerical model employs an 'operator splitting' technique to solve the vorticity-transport equation governing the evolution of vorticity. A semi-Lagrangian scheme is used to update the positions of the vortices during the advective stage of the computation whilst an analytical diffusion algorithm employing Oseen vortices is implemented during the diffusive time step. Redistributing the vorticity analytically instead of using the more traditional random-walk method enables the model to simulate steady flows directly and avoids the n

Keywords