한국연소학회:학술대회논문집
- 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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- Pages.102-111
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- 2004
Level-Set 방법이 적용된 Flame Hole Dynamics 모델을 통한 난류 혼합층 확산화염 모사
Simulation of a Diffusion Flame in Turbulent Mixing Layer by the Flame Hole Dynamics Model with Level-Set Method
초록
Partial quenching structure of turbulent diffusion flames in a turbulent mixing layer is investigated by the method of flame hole dynamics to develope a prediction model for the turbulent lift off. The present study is specifically aimed to remedy the problem of the stiff transition of the conditioned partial burning probability across the crossover condition by adopting level-set method which describes propagating or retreating flame front with specified propagation speed. In light of the level-set simulations with two model problems for the propagation speed, the stabilizing conditions for a turbulent lifted flame are suggested. The flame hole dynamics combined with level-set method yields a temporally evolving turbulent extinction process and its partial quenching characteristics is compared with the results of the previous model employing the flame-hole random walk mapping. The probability to encounter reacting' state, conditioned with scalar dissipation rate, demonstrated that the conditional probability has a rather gradual transition across the crossover scalar dissipation rate in contrast to the stiff transition of resulted from the flame-hole random walk mapping and could be attributed to the finite response of the flame edge propagation.
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