A geometry independent near-wall Reynolds-stress closure

Models proposed for high-Reynolds-number Reynolds-stress closures are, in g eneral, geometry independent. Therefore, they are most suitable for flows w ith complex geometries. With the advent of supercomputers, the near-wall fl ow can be calculated with greater efficiency to give more accurate results on surface properties. However, with modifications made to the various mode ls to account for near-wall behavior, the closures are no longer geometry i ndependent. The cause is the presence of wall distance and wall unit normal s in the proposed corrections for either the velocity-pressure-gradient cor relation tensor, the dissipation rate tensor, the dissipation rate equation , or all of them. In this paper, a proposal is put forward where the modifi cations made to these tensors and equation are free of wall distance and wa ll unit normals. The closure is validated against a wide variety of simple flows and good agreement with data is obtained. Further, the closure is app lied to calculate backstep flows and developing square duct flows. The resu lts are compared with direct numerical simulation and experimental data. In addition, they are also compared with the calculations of another near-wal l Reynolds-stress closure with wall unit normal dependence and is known to give good correlations with backstep flow and square duct flow data. The pr esent closure is found to yield results that are in good agreement with the data and the calculations of the model with wall unit normals. As a result , a viable geometry independent near-wall Reynolds-stress closure is availa ble. (C) 1998 Elsevier Science Ltd. All rights reserved.