A new two-scale model for large eddy simulation of wall-bounded flows

作者：Gungor Ayse Gul; Menon Suresh^*

来源：Progress in Aerospace Sciences, 2010, 46(1): 28-45.

DOI：10.1016/j.paerosci.2009.10.001

• Large eddy simulation
• Two-scale model
• Wall-bounded flows
• Near-wall modeling

A new hybrid approach to model high Reynolds number wall-bounded turbulent flows is developed based on coupling a two-level simulation (TLS) approach (Kemenov and Menon, 2006 [1], 2007 [2] in the inner region with conventional large eddy simulation (LES) away from the wall. This new approach is significantly different from previous near-wall approaches for LES. In this hybrid TLS-LES approach, a very fine small-scale (SS) mesh is embedded inside the coarse LES mesh. The SS equations Capture fine-scale temporal and spatial variations in all three Cartesian directions for all three velocity components near the wall. The TLS-LES equations are derived using a new scale separation operator that allows a smooth transition between the two regions, with the equations in the transition region obtained by blending the TLS large-scale and LES equations. New terms in the hybrid region are identified. The TLS-LES approach is used to study the near-wall features in canonical turbulent channel flows for a range of Reynolds number using relatively coarse large-scale (LS) grids. Results show that the TLS-LES approach is able to capture the effect of both the LS and SS features in the wall region consistently for the range of simulated Reynolds number.

• 出版日期2010-1