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A DYNAMIC SUBGRID‐SCALE MODEL FOR LOW‐REYNOLDS‐NUMBER CHANNEL FLOW
Author(s) -
ZHAO HONG,
VOKE PETER R.
Publication year - 1996
Publication title -
international journal for numerical methods in fluids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.938
H-Index - 112
eISSN - 1097-0363
pISSN - 0271-2091
DOI - 10.1002/(sici)1097-0363(19960715)23:1<19::aid-fld407>3.0.co;2-e
Subject(s) - reynolds number , large eddy simulation , mechanics , filter (signal processing) , flow (mathematics) , scale model , scale (ratio) , mathematics , open channel flow , computational fluid dynamics , statistical physics , physics , turbulence , computer science , engineering , quantum mechanics , computer vision , aerospace engineering
Several issues related to applications of the dynamic subgrid‐scale (SGS) model in large‐eddy simulation (LES) at low Reynolds number are investigated. A modified formulation of the dynamic model is constructed and its performance in low‐Reynolds‐number LES of channel flow is assessed through a comparison of length scales computed respectively by this modified model, the Germano–Lilly dynamic SGS model and two empirical wall damping functions with optimum model coefficients, which have been successfully used in many simulations of channel flows. Two values of the ratio of filter widths are set for each of the dynamic models. The results have confirmed that the modified dynamic SGS model gives the correct behaviour of the subgrid eddy viscosity in the region of a plane wall to an accuracy that exceeds the best‐tuned wall damping function, and almost collapses with the theoretical behaviour of the length scale near the wall without any tuning and adjustment. In addition, the impact of the choice of the ratio of filter widths on the modified dynamic SGS model is found to be much less than with the Germano–Lilly model.