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Large eddy simulations of turbulent swirling flows in a dump combustor: a sensitivity study
Author(s) -
Wang P.,
Bai X. S.
Publication year - 2004
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/fld.781
Subject(s) - turbulence , mechanics , inflow , reynolds number , reynolds stress , outflow , vortex , physics , combustor , large eddy simulation , reynolds averaged navier–stokes equations , reynolds stress equation model , geometry , meteorology , k epsilon turbulence model , mathematics , k omega turbulence model , chemistry , combustion , organic chemistry
Large eddy simulations (LES) of confined turbulent swirling flows in a model dump combustor are carried out. The simulations are based on a high‐order finite difference method on a Cartesian grid, with the sub‐grid scale stress tensor modelled using a scale‐similarity model. The aims of this work are to study the physics of the flow and to evaluate the performance of LES method for simulation of the major features of turbulent swirling flows—the vortex breakdown, the highly anisotropic and fast‐decaying turbulence structure. Influences of inflow/outflow conditions, combustor geometry, inlet swirl profile and Reynolds numbers on the vortex breakdown and turbulence structures are investigated. At very high swirl levels, the influence of the outflow conditions and the outlet geometry is fairly significant, not only at downstream near the outlet, but also at far upstream. At low Reynolds numbers, the onset of vortex breakdown is fairly sensitive to the change of Reynolds number; however, at high Reynolds numbers it is rather insensitive to the Reynolds number. Comparisons of LES results with experimental data are made. The LES results are shown to be in reasonably good agreement with the experimental data if appropriate inflow and outflow boundary conditions are imposed. Copyright © 2004 John Wiley & Sons, Ltd.