Large eddy simulations of turbulent swirling flows in a dump combustor: a sensitivity study
Författare
Summary, in English
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.
Avdelning/ar
Publiceringsår
2005
Språk
Engelska
Sidor
99-120
Publikation/Tidskrift/Serie
International Journal for Numerical Methods in Fluids
Volym
47
Issue
2
Dokumenttyp
Artikel i tidskrift
Förlag
John Wiley & Sons Inc.
Ämne
- Fluid Mechanics and Acoustics
Nyckelord
- boundary conditions
- vortex breakdown
- internal recirculation zone
- swirling flow
- large eddy simulation
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1097-0363