• 에너지공학
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• 제23권1호
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• pp.75-80
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• 2014

지난 최근 몇 년 동안 내연기관 엔진의 여러 가지 타입의 성능, 효율, 배기가스 특성을 잘 설명해 줄 수 있는 흥미있는 수학적인 모델이 다양하게 제시되고 있다. 이러한 다양한 양상의 엔진 작동의 모의실험에 있어서 주요한 요소가 엔진 연소 과정의 모델이다. 연소모델은 주로 세 가지 분류로 세분화 되어지고 있다. 즉, 제로 차원적, 유사 차원적, 다차원 모델로 나눌 수 있다. 제로 차원모델은 열역학 제1법칙에 근거하여 만들어졌고, 시간은 단지 독립 변수이다. 본 연구는 제로 차원 모델에 의하여 스파크 점화 기관의 연소 특성을 제시하려는 그 목적이 있다.

• 한국자동차공학회논문집
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• 제3권3호
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• pp.9-18
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• 1995

The substitution of conventional fuel oil by alternative fuels is of immense interest due to liquid oil shortage and requirements of emission control standard. Among the alternative fuels, natural gas may be the most rational fuel, because of its widespread resource and clean est burning. Meanwhile, engine simulation is of great importance in engine development. Hence a zero-dimensional combustion model was developed for dual-fuel system. Natural gas was injected directly into the cylinder and small amount of distillate was used to provide the ignition kernel for natural gas burning. The intake air and exhaust gas flow was modeled by filling and emptying method. Although the single zone approach has an inherent limitation, the model showed promise as a predictive tool for engine performance. Its simulation was also made to see how the engine performance was influenced by the fuel injection timings and amount of each fuel.

• 한국자동차공학회논문집
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• 제7권9호
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• pp.48-55
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• 1999

In this paper, a zero-dimensional two zone model is developed to investigate the effects of variable valve timing on combustion process in SI engine. The simulation results show that the predicted data has good agreement with experimental ones. The useful information of combustion process such like residual gas fraction cylinder pressure, cylinder temperature and NO concentration can be obtained and the effects of engine variables on combustion processes and performances can be evaluated.

• 오토저널
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• 제5권2호
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• pp.48-55
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• 1983

The prediction of performance and emissions is presented for a spark ignition engine. a two zone, zero-dimensional model was employed which included thermodynamics, combustion and hear transfer, and a kinetic model employed for NOx. The model was used to analyze the processes of compression, combustion and expansion. Cylinder pressures and temperatures were calculated as a function of crankangle as well as engine performance and emissions. Predictions made with the simulation were compared with experimental data from a four cylinder spark ignition engine. Calculated pressures and, Co and Co$_{2}$ concentrations showed acceptable quantitative agreement with data. But calculated No concentrations were slightly different. A parametric study of the effect of variations in speed, combustion duration and spark timing was carried out. This simulation can be useful for design of spark ignition engines.

• 한국자동차공학회논문집
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• 제9권1호
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• pp.28-36
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• 2001

In this study, a zero-dimensional two zone model is developed to investigate the effects of valve overlap period and valve lift on combustion and gas exchange process in SI engine. The simulation results show that the predicted data has good agreements with experimental ones. The useful information of combustion and gas exchange process such as residual gas fraction, cylinder pressure, mass flow rate and volumetric efficiency can be obtained and the effects of engine variables on combustion processes and performances can be evaluated.

• 한국연소학회지
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• 제18권3호
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• pp.9-23
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• 2013

A rotary kiln furnace is one of the most widely used gas-solid reactors in the industrial field. Although the rotary kiln is a versatile system and has different size, approach to the reactor modeling can be generalized in terms of flow motion of the solid and gas phases, heat transfer, and chemical reactions on purpose. In this paper, starting from a zero-dimensional model and extending to higher dimension and comprehensive models, overall procedure of the design development of rotary kiln reactors and considerations are presented. The approaches to performance analysis of the reactors are introduced and examples of application cases are presented.

• 한국항공우주학회지
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• 제49권11호
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• pp.909-917
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• 2021

본 연구에서는 스크램제트 제어모델 정립을 위한 1차원 연소기 해석 솔버가 구축되었다. 유체에 대한 지배방정식 및 아레니우스 식 기반의 연소모델, 연료분사모델이 솔버 내에 구현되었으며, 해석이 수행되었다. 솔버의 검증을 위하여 0차원 점화지연 문제 및 1차원 스크램제트 연소해석 문제가 도입되었으며, 현 솔버가 선행 문헌의 결과들을 성공적으로 재현해 내고 있음을 확인하였다. 이어서 아음속 조건에서의 해석을 위한 램제트 해석 알고리즘이 구축되었으며, 열질식 위치를 통해 램제트 조건에서 연소기 입구 마하수를 확정하는 해석이 수행되었다. 램조건에서 PCST (precombustion shock train) 해석을 위한 모델이 도입되었으며, 천이구간 해석을 위한 알고리즘이 도입되었다. 또한 코드 내 램모드 해석의 적절성을 판단하기 위해 격리부 내 의사충격파 길이를 통해 불시동 발생 여부가 분석되었다.