• 제목/요약/키워드: 축소화학반응기구

검색결과 4건 처리시간 0.019초

디메틸 에테르 착화에 관한 반응기구 축소 연구 (A Study on the Reduction of Reaction Mechanism for the Ignition of Dimethyl Ether)

  • 류봉우;박성욱;이창식
    • 대한기계학회논문집B
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    • 제35권1호
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    • pp.75-82
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    • 2011
  • 디젤의 대체연료인 디메틸 에테르의 반응기구 축소에 관한 수치해석을 수행하였다. 상세반응기구(79 개의 화학종과 351 개의 반응단계)를 기초로, 최대몰농도 해석과 민감도 해석을 균질 반응기 모델에 적용하였다. 축소반응기구는 상세반응기구의 착화지연기간과 비교하여 구축하였는데, 기준값으로 $7.5{\times}10^{-5}$을 적용했을 때 44 개의 화학종과 166 개의 반응단계로 구성된다. 축소반응기구의 계산 정확도를 검증하기 위하여 두 반응기구를 단일영역 균일예혼합 압축착화 엔진모델에 적용하였고, 축소반응기구의 계산결과는 상세반응기구의 결과와 일치하였다. 따라서 본 연구의 축소반응기구는 계산의 정확도의 손실 없이 DME 를 연료로 사용하는 압축착화엔진의 착화 및 연소 과정을 모사하는데 이용될 수 있다.

축소 화학반응 모델링에 의한 탄화수소 연료의 점화지연 특성 (Characteristics of the Ignition Delay for Hydrocarbon Fuels by Reduced Chemical Kinetics Modeling)

  • 김형욱;배상수;민경덕
    • 한국자동차공학회논문집
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    • 제9권4호
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    • pp.44-49
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    • 2001
  • Reduced chemical kinetics mechanism has been derived, which can be applicable for autoignition model of hydrocarbon fuels, and contains 23 reactions and 18 species. The present model is validated with the experimental data, where the ignition delays of several hydrocarbon fuels, such as n-heptane, i-octane, n-decane and DME(dimethylether) are measured as equivalence ratios are varied. Especially, the effects of different fuels on ignition delays can be explained by changing the rate constants of three reactions among the present model. As a result, the proposed model can be applicable to two stage ignition model of Diesel combustion.

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고속 직분식 디젤 엔진에서의 점화지연시기 예측 (Prediction of Ignition Delay for HSDI Diesel Engine)

  • 임재만;김용래;온형석;민경덕
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 추계학술대회
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    • pp.1704-1709
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    • 2004
  • New reduced chemical kinetic mechanism for prediction of autoignition process of HSDI diesel engine was investigated. For precise prediction of the ignition characteristics of diesel fuel, mechanism coefficients were fitted by the experimental results of ignition delay of diesel spray in a constant volume vessel. Ignition delay of diesel engine on various operation condition was calculated based on the new reduced chemical mechanism. The calculation results agreed well with experimental data.

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직접 관계 그래프(DRG)를 이용한 디젤 연료의 상세 화학 반응 기구 축소화 (Skeletal Chemical Mechanisms for a Diesel Fuel Surrogate by the Directed Relation Graph(DRG))

  • 이영재;허강열
    • 한국연소학회지
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    • 제16권2호
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    • pp.16-22
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    • 2011
  • It is a challenging task to apply large detailed chemical mechanisms of fuel oxidation in simulation of complex combustion phenomena. There exist a few systematic methodologies to reduce detailed chemical mechanisms to smaller sizes involving less computational load. This research work concerns generation of a skeletal chemical mechanism by a directed relation graph with specified accuracy requirement. Two sequential stages for mechanism reduction are followed in a perfectly stirred reactor(PSR) for high temperature chemistry and to consider the autoignition delay time for low and high temperature chemistry. Reduction was performed for the detailed chemical mechanism of n-heptane consisting of 561 species and 2539 elementary reaction steps. Validation results show acceptable agreement for the autoignition delay time and the PSR calculation in wide parametric ranges of pressure, temperature and equivalence ratio.