Three-dimensional direct numerical simulation of soot formation and transport in a temporally evolving nonpremixed ethylene jet flame
- Department of Chemical Engineering, University of Utah, Salt Lake City, UT 84098 (United States)
- Reacting Flow Research Department, Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94551 (United States)
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. (author)
- OSTI ID:
- 21116114
- Journal Information:
- Combustion and Flame, Vol. 155, Issue 1-2; Other Information: Elsevier Ltd. All rights reserved; ISSN 0010-2180
- Country of Publication:
- United States
- Language:
- English
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