Darrieus-landau and rayleigh-taylor instabilities in outwardly-propagating, accelerating flames

V. B. Akkerman, Chung King Law

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

Abstract

Expanding reaction fronts are central not only to many laboratory and industrial phenomena, they also constitute such cosmic phenomena as the thermonuclear combustion in supernovae. While in terrestrial conditions the effect of intrinsic flamefront instabilities is generally believed to be supplementary to, say, external turbulence and chamber dynamics, at the astrophysical scale the role of instabilities in the flame acceleration is presumably dominant. Moreover, while in terrestrial systems we focus mainly on the hydrodynamic, Darrieus-Landau (DL) instability, the Rayleigh-Taylor (RT; body-force) instability is a key issue for supernovae flames because of the enormous gravity. Within the 0th-order approach, the DL instability is irrelevant to the perturbation wave numbers, hence leading to a globally-spherical structure of the flamefront. In contrast, however, the RT instability is favored at large scales. Consequently, if RT instability dominates over that of DL, the globally-spherical flamefront can be replaced by an "8"-like bubble rising outwardly. In the present work we develop a self-similar formulation describing a globally-spherical expanding flamefront corrugated due to the DL instability in a central gravitation filed. The associated scenario of the flame acceleration, the evolution of the upstream flow, and the locus of the deflagration-to-detonation transition (DDT) are determined. We also compare the effects of DL and RT instabilities, estimating whether a globally-spherical DL-corrugated flamefront is subsequently converted to a RT bubble. It is shown how the locus of such a conversion is coupled to various flame and flow parameters.

Original languageEnglish (US)
Title of host publicationFall Technical Meeting of the Eastern States Section of the Combustion Institute 2011
PublisherCombustion Institute
Pages625-631
Number of pages7
ISBN (Electronic)9781622761258
StatePublished - Jan 1 2011
EventFall Technical Meeting of the Eastern States Section of the Combustion Institute 2011 - Storrs, United States
Duration: Oct 9 2011Oct 12 2011

Publication series

NameFall Technical Meeting of the Eastern States Section of the Combustion Institute 2011

Other

OtherFall Technical Meeting of the Eastern States Section of the Combustion Institute 2011
CountryUnited States
CityStorrs
Period10/9/1110/12/11

All Science Journal Classification (ASJC) codes

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

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  • Cite this

    Akkerman, V. B., & Law, C. K. (2011). Darrieus-landau and rayleigh-taylor instabilities in outwardly-propagating, accelerating flames. In Fall Technical Meeting of the Eastern States Section of the Combustion Institute 2011 (pp. 625-631). (Fall Technical Meeting of the Eastern States Section of the Combustion Institute 2011). Combustion Institute.