Keywords

soot, direct numerical simulation, nonpremixed, turbulent combustion, ethylene, jet flame

Abstract

Three-dimensional direct numerical simulation of soot formation with complex chemistry is presented. The simulation consists of a temporally evolving, planar, nonpremixed ethylene jet flame with a validated, 19-species reduced mechanism. A four-step, three-moment, semiempirical soot model is employed. Previous two-dimensional decaying turbulence simulations have shown the importance of multidimensional flame dynamical effects on soot concentration [D.O. Lignell, J.H. Chen, P.J. Smith, T. Lu, C.K. Law, Combust. Flame 151 (1–2) (2007) 2–28]. It was shown that flame curvature strongly impacts the diffusive motion of the flame relative to soot (which is essentially convected with the flow), resulting in soot being differentially transported toward or away from the flame zone. The proximity of the soot to the flame directly influences soot reactivity and radiative properties. Here, the analysis is extended to three dimensions in a temporal jet configuration with mean shear. Results show that similar local flame dynamic effects of strain and curvature are important, but that enhanced turbulent mixing of fuel and oxidizer streams has a first-order effect on transport of soot toward flame zones. Soot modeling in turbulent flames is a challenge due to the complexity of soot formation and transport processes and the lack of detailed experimental soot–flame–flow structural data. The present direct numerical simulation provides the first step toward providing such data.

Original Publication Citation

David O. Lignell, Jacqueline H. Chen, Philip J. Smith, Three-dimensional direct numerical simulation of soot formation and transport in a temporally evolving nonpremixed ethylene jet flame, Combustion and Flame, Volume 155, Issues 1–2, 2008, Pages 316-333, ISSN 0010-2180, https://doi.org/10.1016/j.combustflame.2008.05.020.

Document Type

Peer-Reviewed Article

Publication Date

2008-07-18

Publisher

Combustion and Flame

Language

English

College

Ira A. Fulton College of Engineering

Department

Chemical Engineering

University Standing at Time of Publication

Full Professor

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