Large-eddy simulation of turbulence with the stretched-vortex SGS model

Dale Pullin, Graduate Aeronautical Laboratories, California Institute of Technology, USA

Results will be presented obtained from large-eddy simulation (LES) of turbulence based on the stretched-vortex SGS model. Examples presented will begin with decaying homogeneous turbulence. Issues associated with LES of compressible turbulence will be considered. The stretched-vortex, SGS modeling of the mixing of a passive scalar by turbulence will be discussed including the effect of Schmidt number. Other flows described will include incompressible, non-rotating and rotating channel flow and shock-induced mixing produced by both planar and cylindrically-implosive Richtmyer-Meshkov instability. For the latter flows, we will develop a form of multi-scale modeling of some turbulence statistics obtained by subgrid continuation of spectra and probability density functions. The severe road block posed by the need for near-wall modeling of wall-bounded turbulent flows will be discussed. A possible solution for this consisting of a special near-wall element that combines the stretched-vortex SGS model with concepts based on local-inner scaling and a virtual wall will be presented, along with related LES of channel flows at bulk Reynolds numbers of order one million.