Flame Propagation through Large-Scale Vortical Flows: Effect of Equivalence Ratio

L. Kagan; G. Sivashinsky

Mathematical Modelling of Natural Phenomena (2010)

  • Volume: 2, Issue: 2, page 13-19
  • ISSN: 0973-5348

Abstract

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The present work is a continuation of previous studies of premixed gas flames spreading through a space-periodic array of large-scale vorticities, and is motivated by the experimentally known phenomenon of flame extinction by turbulence. The prior work dealt with the strongly non-stoichiometric limit where the reaction rate is controlled by a single (deficient) reactant. In the present study the discussion is extended over a physically more realistic formulation based on a bimolecular reaction involving two reactants with different molecular diffusivities, and where the mixture equivalence ratio is utilized as a control param- eter. The flow-field is considered as prescribed and unaffected by combustion. The results obtained show that the dual influence of the large-scale turbulence on premixed combustion (flame speed enhancement followed by its reduction and extinction), and higher resilience of turbulent flames at lower Lewis numbers, are not actually related to the multiple-scale nature of the flow-field; the effects may well be captured within the framework of a one-scale flame-flow interaction scheme.


How to cite

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Kagan, L., and Sivashinsky, G.. "Flame Propagation through Large-Scale Vortical Flows: Effect of Equivalence Ratio." Mathematical Modelling of Natural Phenomena 2.2 (2010): 13-19. <http://eudml.org/doc/222184>.

@article{Kagan2010,
abstract = { The present work is a continuation of previous studies of premixed gas flames spreading through a space-periodic array of large-scale vorticities, and is motivated by the experimentally known phenomenon of flame extinction by turbulence. The prior work dealt with the strongly non-stoichiometric limit where the reaction rate is controlled by a single (deficient) reactant. In the present study the discussion is extended over a physically more realistic formulation based on a bimolecular reaction involving two reactants with different molecular diffusivities, and where the mixture equivalence ratio is utilized as a control param- eter. The flow-field is considered as prescribed and unaffected by combustion. The results obtained show that the dual influence of the large-scale turbulence on premixed combustion (flame speed enhancement followed by its reduction and extinction), and higher resilience of turbulent flames at lower Lewis numbers, are not actually related to the multiple-scale nature of the flow-field; the effects may well be captured within the framework of a one-scale flame-flow interaction scheme.
},
author = {Kagan, L., Sivashinsky, G.},
journal = {Mathematical Modelling of Natural Phenomena},
keywords = {flame-flow interaction; turbulent flames; flammability limits},
language = {eng},
month = {3},
number = {2},
pages = {13-19},
publisher = {EDP Sciences},
title = {Flame Propagation through Large-Scale Vortical Flows: Effect of Equivalence Ratio},
url = {http://eudml.org/doc/222184},
volume = {2},
year = {2010},
}

TY - JOUR
AU - Kagan, L.
AU - Sivashinsky, G.
TI - Flame Propagation through Large-Scale Vortical Flows: Effect of Equivalence Ratio
JO - Mathematical Modelling of Natural Phenomena
DA - 2010/3//
PB - EDP Sciences
VL - 2
IS - 2
SP - 13
EP - 19
AB - The present work is a continuation of previous studies of premixed gas flames spreading through a space-periodic array of large-scale vorticities, and is motivated by the experimentally known phenomenon of flame extinction by turbulence. The prior work dealt with the strongly non-stoichiometric limit where the reaction rate is controlled by a single (deficient) reactant. In the present study the discussion is extended over a physically more realistic formulation based on a bimolecular reaction involving two reactants with different molecular diffusivities, and where the mixture equivalence ratio is utilized as a control param- eter. The flow-field is considered as prescribed and unaffected by combustion. The results obtained show that the dual influence of the large-scale turbulence on premixed combustion (flame speed enhancement followed by its reduction and extinction), and higher resilience of turbulent flames at lower Lewis numbers, are not actually related to the multiple-scale nature of the flow-field; the effects may well be captured within the framework of a one-scale flame-flow interaction scheme.

LA - eng
KW - flame-flow interaction; turbulent flames; flammability limits
UR - http://eudml.org/doc/222184
ER -

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