A hybrid LES/RANS approach using an anisotropy-resolving algebraic turbulence model

In order to derive a possible path for developing a large eddy simulation (LES) applicable to high Reynolds-number turbulent flows, a hybrid approach connecting LES with the Reynolds-averaged Navier-Stokes (RANS) modeling in the near-wall region is studied. In contrast to most of the previous studies that have employed linear eddy-viscosity models. in this study, an advanced nonlinear eddy-viscosity model is introduced to resolve the near-wall stress anisotropy more correctly. To investigate the model performance in detail, the proposed model is applied to fully-developed plane channel flows with various grid resolutions and at various Reynolds numbers. The grid resolution in the streamwise (x) and spanwise (z) directions ranges from 10(1) to 10(3) in wall unit (Deltax(+) or Deltaz(+)), while y(wall)(+) similar to 1 in the wall-normal (y) direction. The present model provides encouraging, results for further development of this kind of hybrid LES/RANS model. (C) 2004 Elsevier Inc. All rights reserved.