Simultaneous visualization of OH, CH, CH2O and toluene PLIF in a methane jet flame with varying degrees of turbulence
Författare
Summary, in English
This paper presents simultaneous, single shot planar laser-induced fluorescence (PLIF) imaging of four species: OH, CH, CH2O (formaldehyde) and toluene (C6H5CH3) in methane/air jet flames. The jet flames were stabilized by a flat pilot flame generated using a McKenna type burner. Both flames were operated with a stoichiometric premixed methane/air mixture at room temperature and atmospheric pressure. Several flames, with varying jet flow speeds, were investigated, spanning from laminar (10 m/s jet exit velocity) up to highly turbulent flame conditions, with high Karlovitz numbers, (150 m/s jet exit velocity). Measuring the four species presented above provides detailed information on jet flame structures including the transition from fuel (indicated by the fuel tracer toluene) via the preheat zone (indicated by CH2O) and the inner layer of the flame front (indicated by CH) to the oxidation layer and the postflame zone (both indicated by OH). Furthermore, the simultaneously recorded PLIF images enable the study of correlations between these key species. Especially, overlapping regions between the species in the flames is of interest. The result indicates that turbulence in the present jet flames affects primarily the mixing in the preheat zone and the wrinkling of the reaction layers. It does however not significantly affect the inner flame front structures, represented by the CH radicals, as the thickness of the CH layer remains fairly constant under the investigated flame conditions. (C) 2012 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
Publiceringsår
2013
Språk
Engelska
Sidor
1475-1482
Publikation/Tidskrift/Serie
Proceedings of the Combustion Institute
Volym
34
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Atom and Molecular Physics and Optics
- Fluid Mechanics and Acoustics
Nyckelord
- PLIF
- Jet flame
- Simultaneous
- Reaction zones
- Turbulence-combustion
- interaction
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 1540-7489