• Title/Summary/Keyword: Saffman-Taylor 불안정성

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Investigation of Premixed Flame Instability with Heat and Momentum Losses (열 및 운동량 손실이 예혼합화염의 연소불안정성에 미치는 영향에 관한 연구)

  • Kang Sang Hun;Baek Seung Wook;Im Hong Geun
    • Journal of the Korean Society of Propulsion Engineers
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    • v.9 no.3
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    • pp.101-119
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    • 2005
  • For MEMS applications, the effects of the momentum and heat loss on the stability of laminar premixed flames in a narrow channel are investigated by high-fidelity numerical simulations. A general finding is that momentum loss promotes the Saffman-Taylor (S-T) instability which is additive to the Darrieus-Landau (D-L) instabilities, while the heat loss effects result in an enhancement of the diffusive-thermal (D-T) instability. These effects are also valid in nonlinear behavior of the premixed flame. The simulations of multiple cell interactions are also conducted with heat and momentum loss effects.

Combustion instabilities of the Premixed flame in Micro-Channel (미소채널 내에서의 예혼합화염의 연소불안정성)

  • Kang, Sang-Hun;Baek, Seung-Wook;Im, Hong-G.
    • 한국연소학회:학술대회논문집
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    • 2003.05a
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    • pp.209-214
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    • 2003
  • The Saffman-Taylor instability mechanisms in laminar premixed flames in a Hele-Shaw cell are investigated using two-dimensional numerical simulations with Poiseuille assumption for the viscous effect. The baseline calculations considering the Darrieus-Landau and diffusive-thermal instability modes show the results consistent with the classical linear instability theory. With the Saffrnan-Taylor instability mechanism. the overall effect is to enhance the destabilizing mechanism by providing an increased viscous force in the product gas. The linear instability behavior is found to qualitatively similar to the Darrieus-Landau mechanism. However, the results in the nonlinear range demonstrate that there may exist distinct characteristic time scales associated with Darrieus-Landau and Saffman-Taylor mechanisms, such that the latter effect sustains longer in time, contributing to a higher overall flame speed.

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Numerical Study on the Premixed Flame Instability and Nonlinear Behavior (예혼합화염의 불안정성 및 비선형적 거동에 관한 수치적 연구)

  • Kang, Sang-Hun;Baek, Seung-Wook;Im, Hong G.
    • 한국연소학회:학술대회논문집
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    • 2005.10a
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    • pp.281-286
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    • 2005
  • To understand fundamental characteristics of combustion in a small scale device, the effects of the momentum and heat loss on the stability of laminar premixed flames in a narrow channel are investigated by two-dimensional high-fidelity numerical simulation. A general finding is that momentum loss promotes the Saffman-Taylor (S-T) instability which is additive to the Darrieus-Landau (D-L) instabilities, while the heat loss effects result in an enhancement of the diffusive-thermal (D-T) instability. These effects are also valid in nonlinear behavior of the premixed flame. The simulations of multiple cell interactions are also conducted with heat and momentum loss effects.

  • PDF