DEVELOPMENTS IN A LOW-REYNOLDS-NUMBER 2ND-MOMENT CLOSURE AND ITS APPLICATION TO SEPARATING AND REATTACHING FLOWS

The paper describes further developments of the low-Reynolds-number se cond-moment closure of Craft and Launder (1996), and reports its appli cation to separating and reattaching flows. The specific flows conside red are the axisymmetric diffuser flows of Stieglmeier et al. (1989), and the backward facing step flows reported by Driver and Seegmiller ( 1983) and Le et al. (1997). It is shown that modifications to the pres sure strain model, including inhomogeneity effects on the mean velocit y gradients, allow the large shear stress values found experimentally in the recirculation region to be captured. An elaboration of the (alg ebraic) approximation for the triple moments is also proposed which im proves the prediction of the recirculation and recovery region. (C) 19 98 Elsevier Science Inc. All rights reserved.