Modeling of turbulent, two-dimensional nonpremixed CH{sub 4}/H{sub 2} flame over a bluffbody using first- and second-order elliptic conditional moment closures

Journal Article · Sat Oct 01 00:00:00 EDT 2005 · Combustion and Flame

DOI:https://doi.org/10.1016/j.combustflame.2005.05.008· OSTI ID:20677715

Sreedhara, S; Huh, Kang Y ^[1]

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1. Department of Mechanical Engineering, Pohang University of Science &

First- and second-order conditional moment closure (CMC) models are applied to a turbulent CH{sub 4}/H{sub 2} flame anchored on a bluffbody. Significant extinction is involved as the jet velocity increases for the three test flames: HM1, HM2, and HM3 (in a turbulent nonpremixed flame (TNF) database). The flow and mixing field are calculated with the k-| model with a modified constant, C{sub |1}. Elliptic CMC formulation is employed to calculate reacting scalar fields with chemical kinetic mechanisms, GRI Mech 2.11 and 3.0. Second-order corrections are limited to three rate-limiting steps to avoid solving a huge number of variance and covariance equations. Even though first-order CMC captures temperature and major species within agreeable limits, the predictions of OH and NO are considerably improved with second-order CMC in both mixture fraction and real space. Results show that the equilibrium assumption performs better than the cold mixture as the conditional inflow boundary condition. There is no noticeable conditional cross-stream dependence downstream, while care needs to be taken in interpretation of the upstream results near the nozzle.

• OSTI ID: 20677715
• Journal Information: Combustion and Flame, Vol. 143, Issue 1-2; 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
METHANE
HYDROGEN
TURBULENCE
MATHEMATICAL MODELS
FLAMES