Extinction and near-extinction instability of non-premixed tubular flames

Journal Article · Thu Jan 15 04:00:00 EST 2009 · Combustion and Flame

DOI:https://doi.org/10.1016/J.COMBUSTFLAME.2008.09.004· OSTI ID:21227377

Hu, Shengteng; Pitz, Robert W; Yu, Wang ^[1]

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1. Mechanical Engineering Department, Vanderbilt University, Nashville, TN 37235 (United States)

Tubular non-premixed flames are formed by an opposed tubular burner, a new tool to study the effects of curvature on extinction and flame instability of non-premixed flames. Extinction of the opposed tubular flames generated by burning diluted H{sub 2}, CH{sub 4} or C{sub 3}H{sub 8} with air is investigated for both concave and convex curvature. To examine the effects of curvature on extinction, the critical fuel dilution ratios at extinction are measured at various stretch rates, initial mixture strengths and flame curvature for fuels diluted in N{sub 2}, He, Ar or CO{sub 2}. In addition, the onset conditions of the cellular instability are mapped as a function of stretch rates, initial mixture strengths, and flame curvature. For fuel mixtures with Lewis numbers much less than unity, such as H{sub 2}/N{sub 2}, concave flame curvature towards the fuel suppresses cellular instabilities. (author)

• OSTI ID: 21227377
• Journal Information: Combustion and Flame, Journal Name: Combustion and Flame Journal Issue: 1 Vol. 156; ISSN CBFMAO; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
AIR
ARGON
BURNERS
CARBON DIOXIDE
DILUTION
FLAME EXTINCTION
FLAMES
HELIUM
HYDROGEN
INSTABILITY
METHANE
MIXTURES
NITROGEN
PROPANE
TUBES