Structure and stabilization mechanism of a stratified premixed low swirl flame
Författare
Summary, in English
This paper presents numerical and experimental investigations of the structure and stabilization of a low swirl turbulent stratified lean premixed methane/air flame. Large-eddy simulations are performed using a two-scalar flamelet model based on mixture fraction for predicting the stratification in the fuel/air mixture and a level-set G-function for tracking the flame. Measurements are carried out with LDV for velocity field and simultaneous PLIF of OH radicals and fuel tracer acetone to identify the structures of the flame. The leading edge flame front is observed to exhibit large-scale flame front wrinkling with a particular W-shaped front frequently occurring. This structure is formed due to the interaction of flame front with the large-scale flow motion in the inner low speed zone and the outer high-speed shear-layer of the burner. The W-structures are formed and destroyed periodically at 15 Hz. The flame stabilization is shown to be dictated by the large-scale vortex rings in the shear-layer. This flame stabilization mechanism is rather different from that found in typical bluff-body stabilized flames and high-swirl flames. (C) 2010 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
Publiceringsår
2011
Språk
Engelska
Sidor
1567-1574
Publikation/Tidskrift/Serie
Proceedings of the Combustion Institute
Volym
33
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Atom and Molecular Physics and Optics
- Fluid Mechanics and Acoustics
Nyckelord
- Low-swirl flame
- Lean premixed flame stabilization
- Flame structures
- Laser diagnostics
- Large eddy simulation
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1540-7489