High resolution imaging of flameless and distributed turbulent combustion
Författare
Summary, in English
Planar laser-induced fluorescence (PLIF) and Rayleigh scattering measurements were used for the study of turbulence/combustion interactions in distributed reaction regimes including flameless or MILD combustion. A novel laboratory scale burner (Distributed and Flameless Combustion Burner - DFCB) was used to reach uniquely high Karlovitz numbers, presently reported up to 14,400. It consists of a highly turbulent piloted high speed jet burner with a vitiated coflow. Six cases are reported whereas two of them (leaner cases) led to an invisible reacting zone, though still emitting light in the UV and near infrared range. Simultaneous OH/CH(2)O PLIF image with 50 mu m spatial resolution were achieved to capture the variation of intermediate species in the reaction layer. When complemented with temperature images obtained by Rayleigh scattering measurement, it provided insights of the reaction front structures as well as measures of the flame brush thicknesses. In particular, variations in the jet velocity highlighted the influence of turbulent mixing (hence turbulence/chemistry interaction) on the flame structures as depicted by the formation of relatively large pools of CH(2)O. Further, variations in the jet stoichiometry impacted on the reaction zone visibility but only marginally on the intensity and moderately on the overall shape of the OH and CH(2)O signals. (C) 2011 The Combustion Institute. Published by Elsevier Inc. All rights reserved.
Avdelning/ar
Publiceringsår
2012
Språk
Engelska
Sidor
306-316
Publikation/Tidskrift/Serie
Combustion and Flame
Volym
159
Issue
1
Länkar
Dokumenttyp
Artikel i tidskrift
Förlag
Elsevier
Ämne
- Atom and Molecular Physics and Optics
Nyckelord
- Flameless combustion
- Distributed reaction regime
- Turbulence/chemistry
- interaction
- Planar laser-induced fluorescence
- Rayleigh scattering
Status
Published
ISBN/ISSN/Övrigt
- ISSN: 0010-2180