Numerical study of turbulent flow over two-dimensional surface-mounted ribs in a channel

This study accurately predicts the cases of turbulent flow around a surface -mounted two-dimensional rib with varying lengths. The numerical method emp loys a differencing scheme for integrating the elliptic Reynolds-averaged N avier-Stokes equations and the continuity equation. A two-equation k-epsilo n turbulence model is employed to simulate the turbulent transport quantiti es and close the solving problem. The near-wall regions of the separated si des of the rib are resolved by a near-wall model of a two-layer approach in stead of the.wall function approximation. Computations for flow over a surf ace-mounted rectangular rib are conducted for the variations in the rib len gths. Results indicate that upstream of the obstacle, the length of the rec irculating region remains unchanged with varying rib lengths; while the dow nstream length of the recirculating region is a strong function of rib leng th and changes nearly linearly for the varying lengths of B/H = 0.1 to B/H = 4.0. Reattachment on top of the rib, owing to its increasing length, affe cts the downstream boundary layer development. Copyright (C) 1999 John Wile y & Sons, Ltd.