Premixed flames in stagnating turbulence. Part VI. Predicting the mean density and the permitted rates of strain for impinging reactant streams

Journal Article · Sun Feb 15 00:00:00 EST 2009 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2008.10.024· OSTI ID:21137918

Bray, Ken ^[1]; Champion, Michel ^[2]; Libby, Paul A ^[3]

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1. Cambridge University, Cambridge CB2 1PZ (United Kingdom)
2. Laboratoire de Combustion et de Detonique, UPR9028, CNRS, ENSMA, 86961 Futuroscope (France)
3. University of California San Diego, La Jolla, CA 92093 (United States)

A RANS analysis of a jet of premixed reactants impinging on a wall is presented. Unlike previous related studies by the same authors, in which the mean density distribution through the flame brush is specified from experiment in order to concentrate on the fluid mechanics of the problem, the mean density is computed in the present work. As a consequence, an appropriate description for the mean rate of heat release is required. The presumed PDF model selected for this purpose, with strong support from relevant DNS, is supplemented with a new model for the mean scalar dissipation rate. Illustrative numerical results are presented and it is shown that an approximately sixfold increase in a mean strain rate function is required to displace the flame from a location where flashback to the nozzle is about to occur to a position so close to the wall that extinction is imminent. Comparisons of predicted mean property distributions with published experimental data are found to be satisfactory and to lend support to the proposed model. (author)

• OSTI ID: 21137918
• Journal Information: Combustion and Flame, Vol. 156, Issue 2; Other Information: Elsevier Ltd. All rights reserved; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
DENSITY
FLAME EXTINCTION
FLAMES
COMPARATIVE EVALUATIONS
DISTRIBUTION
HEAT LOSSES
SCALARS
TURBULENCE
WALLS
STRAIN RATE
FLASHBACK
PARTITION FUNCTIONS
JETS
NOZZLES
STAGNATION
MATHEMATICAL MODELS
Turbulent premixed flames
Chemical production rate
Scalar variance
Stagnating flows