Enhancement of flame blowout limits by the use of swirl

Journal Article · Tue May 01 04:00:00 EDT 1990 · Combustion and Flame; (USA)

DOI:https://doi.org/10.1016/0010-2180(90)90126-C· OSTI ID:6612449

Feikema, D; Chen, R H; Driscoll, J F ^[1]

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1. Michigan Univ., Ann Arbor, MI (USA). Dept. of Aerospace Engineering

The blowout limits of a number of swirl-stabilized, nonpremixed flames were measured, and the observed trends are successfully explained by applying certain concepts that previously have been applied only to nonswirling flames It is shown that swirl flame blowout limits can be compared to well-known limits for nonswirling simple diffusion flames by using the proper nondimensional parameter, i.e., the inverse Damkohler number ({ital U{sub F}/d{sub F}})/({ital S{sub L}}{sup 2}/{alpha}{sub {ital F}}). The fuel velocity at blowout ({ital U{sub F}}) was measured while four parameters were systematically varied: the fuel tube diameter ({ital d{sub F}}), the fuel type and thus reaction rate, which is related to the maximum laminar burning velocity ({ital S{sub L}}), the coaxial air velocity ({ital U{sub A}}), and the swirl number. Results show that for zero swirl, the blowout curves agree with curves predicted by previous analysis. However, as swirl is added, the flame becomes five times more stable (based on maximum fuel velocity). To explain the effect of swirl, a simple analysis is presented that is an extension of previous nonswirling flame blowout theory.

• OSTI ID: 6612449
• Journal Information: Combustion and Flame; (USA), Journal Name: Combustion and Flame; (USA) Vol. 80:2; ISSN 0010-2180; ISSN CBFMA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800* -- Combustion
Pyrolysis
& High-Temperature Chemistry
42 ENGINEERING
421000 -- Engineering-- Combustion Systems
ACCIDENTS
BLOWOUTS
DIFFUSION
FLAME PROPAGATION
FLAMES
FLUID FLOW
HYDROGEN ADDITIONS
LAMINAR FLOW
PARAMETRIC ANALYSIS
TUBES
VELOCITY
VORTEX FLOW