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Title: Chemical closure and burning rates in premixed turbulent flames

Conference · · Combustion and Flame; (United States)
OSTI ID:6537872
 [1];  [2]
  1. Cornell Univ., Ithaca, NY (United States). School of Mechanical and Aerospace Engineering
  2. Sandia National Labs., Livermore, CA (United States)

Chemical closure for premixed turbulent flames is considered, and with a small number of assumptions regarding its form, a model expression for the mean rate of product formation is obtained: w = C[sub p]c(1 [minus] c) to fourth order in (c [minus] 1/2), with C[sub p] a proportionality factor. Any model regardless of its physical and chemical basis should give this result if the aforementioned assumptions are satisfied. The burning rate integral, B[sub T], is introduced, and a relationship between B[sub T] and C[sub p] is developed: B[sub T] = C[sub p]l[sub B] where l[sub B] is a measure of the flame thickness. It follows that measurements of B[sub T] can be used to find C[sub p], and that measurements of this type for a broad range of conditions can provide an empirical closure for w good to fourth order in (c [minus] 1/2). A method for measuring B[sub T] based on a control volume analysis and the use of conditional mean velocities is proposed and demonstrated with data from Miles. The model expression for w is specialized to the flamelet regime of turbulent combustion, and the result obtained is similar to the Bray, Moss, Champion and Libby crossing density model expression. A clear physical interpretation for C[sub p] valid for the flamelet regime, is offered.

OSTI ID:
6537872
Report Number(s):
CONF-940711-; CODEN: CBFMAO
Journal Information:
Combustion and Flame; (United States), Vol. 100:1-2; Conference: 25. international symposium on combustion, Irvine, CA (United States), 31 Jul - 5 Aug 1994; ISSN 0010-2180
Country of Publication:
United States
Language:
English