Finite rate chemistry and presumed PDF models for premixed turbulent combustion

Journal Article · Fri Sep 15 00:00:00 EDT 2006 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2006.07.001· OSTI ID:20824152

Bray, K N.C.; Swaminathan, N ^[1]; Champion, M ^[2]; Libby, P A ^[3]

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

The sensitivity of the prediction of mean reaction rates in turbulent premixed flames to presumed PDF shape is studied. Three different presumed PDF shapes are considered: (i) a beta function PDF, (ii) a twin delta function PDF, and (iii) a PDF based on unstrained laminar flame properties. The unstrained laminar flame has the same thermochemistry as the turbulent flame. Emphasis is placed on capturing the finite rate chemistry effects and obtaining a simple expression for the mean reaction rate. It is shown that, as the PDFs approach their bimodal limit, the mean reaction rate expressions obtained using the above three PDFs reduce to a common form. These expressions differ only in the numerical value of a multiplying factor. Predictions are compared with DNS data. Under the conditions of this comparison, the beta function and twin delta function PDFs lead to significant errors, while the PDF based on properties of an unstrained laminar flame gives good agreement with the DNS. (author)

• OSTI ID: 20824152
• Journal Information: Combustion and Flame, Vol. 146, Issue 4; 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
COMBUSTION KINETICS
TURBULENCE
MATHEMATICAL MODELS
SENSITIVITY ANALYSIS
ACCURACY