An asymptotic theory of laminar premixed flames in dense fluids

D. Fong, J. K. Bechtold, C. K. Law

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We derive an asymptotic theory of laminar premixed flames in high density fluids in the limit of large activation energy. The model is intended to provide insights into the structure and dynamics of deagration waves in high pressure, dense fluids where nor- mal Fickian diffusion is limited. In such cases, particularly under conditions exceeding the thermodynamic critical point of the fluid, the primary mode of species transport is through cross-diffusion, i.e. the Soret effect. Such a model for diffusive transport is considered, and we derive a model with an explicit dependence on the Soret effect for a one-step overall reaction. The density is assumed sufficiently high to adopt a constant density formulation. The local reaction-diffusion structure is found to be fundamentally different from that of an ideal gas with Fickian diffusion, which results in new conditions relating the equations for thermal and mass transport in the bulk flow. The model is used to investigate the basic structure of planar flames, as well as their stability. Stability boundaries are identified that mark the transition from planar to either steady, spatially periodic structures, or time-dependent modes of propagation. The combined effects of the Soret diffusion coefficient and Lewis number are discussed.

Original languageEnglish (US)
Title of host publicationWestern States Section of the Combustion Institute Spring Technical Meeting 2012
PublisherWestern States Section/Combustion Institute
Pages517-525
Number of pages9
ISBN (Electronic)9781622761241
StatePublished - Jan 1 2012
EventWestern States Section of the Combustion Institute Spring Technical Meeting 2012 - Tempe, United States
Duration: Mar 19 2012Mar 20 2012

Publication series

NameWestern States Section of the Combustion Institute Spring Technical Meeting 2012

Other

OtherWestern States Section of the Combustion Institute Spring Technical Meeting 2012
CountryUnited States
CityTempe
Period3/19/123/20/12

All Science Journal Classification (ASJC) codes

  • Mechanical Engineering
  • Chemical Engineering(all)
  • Physical and Theoretical Chemistry

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  • Cite this

    Fong, D., Bechtold, J. K., & Law, C. K. (2012). An asymptotic theory of laminar premixed flames in dense fluids. In Western States Section of the Combustion Institute Spring Technical Meeting 2012 (pp. 517-525). (Western States Section of the Combustion Institute Spring Technical Meeting 2012). Western States Section/Combustion Institute.