• 제목/요약/키워드: Saffman-Taylor instability

검색결과 3건 처리시간 0.014초

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

  • 강상훈;백승욱;임홍근
    • 한국추진공학회지
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    • 제9권3호
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    • pp.101-119
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    • 2005
  • 초소형 연소시스템의 응용을 위한 기초 자료로서, 열 및 운동량 손실이 예혼합화염의 연소불안정성에 미치는 영향에 대하여 수치적으로 연구하였다 고차정확도를 갖는 수치해석기법을 이용한 수치실험에서 운동량 손실은 Darrieus-Landau (D-L) 불안정성을 증진시키는 효과를 보였고 열손실은 diffusive-thermal (D-T) 불안정성을 활성화시키는 효과를 나타냈다. 이러한 영향은 화염의 비선형적 거동구간에도 유효하여 다중 셀의 분할 및 통합과정에서도 중요한 역할을 했다.

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

  • 강상훈;백승욱;임홍근
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 제26회 KOSCO SYMPOSIUM 논문집
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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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예혼합화염의 불안정성 및 비선형적 거동에 관한 수치적 연구 (Numerical Study on the Premixed Flame Instability and Nonlinear Behavior)

  • 강상훈;백승욱;임홍근
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2005년도 제31회 KOSCO SYMPOSIUM 논문집
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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.

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