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Record Details

Record 25 of 65785
Direct simulations of premixed turbulent flames with nonunity Lewis numbers
External Online Source: doi:10.1016/0010-2180(93)90018-X
Author and Affiliation:
Rutland, C. J.(NASA Ames Research Center, Moffett Field, CA, United States)
Trouve, A.(Wisconsin Univ., Madison)
Abstract: A principal effect of turbulence on premixed flames in the flamelet regime is to wrinkle the flame fronts. For nonunity Lewis numbers, Le is not equal to 1, the local flame structure is altered in curved regions. This effect is examined using direct numerical simulations of 3D isotropic turbulence with constant density, single-step Arrhenius kinetics chemistry. Simulations of Lewis numbers 0.8, 1.0, and 1.2 are compared. At the local level, curvature effects dominated changes to the flame structure while strain effects were insignificant. A strong Lewis-number-dependent correlation was found between surface curvature and the local flame speed. The correlation was positive for Le less than 1 and negative for Le greater than 1. At the global level, strain-related effects were more significant than curvature effects. The turbulent flame speed changed significantly with Lewis number, increasing as Le decreased. This was found to be due to strain effects that have a nonzero mean over the flame surface, rather than to curvature effects that have a nearly zero mean. The mean product temperature was also found to vary with Lewis number, being higher for Le greater than 1 and lower for Le less than 1.
Publication Date: Jul 01, 1993
Document ID:
19930062006
(Acquired Dec 28, 1995)
Accession Number: 93A46003
Subject Category: INORGANIC AND PHYSICAL CHEMISTRY
Document Type: Journal Article
Publication Information: Combustion and Flame (ISSN 0010-2180); 94; 1-2; p. 41-57.
Publisher Information: United States
Financial Sponsor: NASA; United States
Organization Source: NASA Ames Research Center; Moffett Field, CA, United States
Description: 17p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: Copyright
NASA Terms: FLAME PROPAGATION; MATHEMATICAL MODELS; PREMIXED FLAMES; PROPAGATION VELOCITY; TURBULENT COMBUSTION; COMBUSTION CHEMISTRY; LEWIS NUMBERS; REACTION KINETICS; STRAIN RATE
Imprint And Other Notes: Combustion and Flame vol. 94, no. 1-2 p. 41-57. July 1993
Miscellaneous Notes: Research supported by Stanford Univ
Availability Source: Other Sources
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