• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3329-3334
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• 2007

The purpose of the research is to investigate of diesel spray combustion for simultaneously reduce way NOx and PM. The pressure diesel injection were done into intermediates that are generated by very lean DME HCCI combustion using a RCM. The concentration of intermediate could not be directly measured; we estimated it by CHEMKIN calculation. DME HCCI characteristic is surveyed. Validations of the CHEMKIN calculation were confirmed pressure rise of an experiment and pressure rise of a calculation. Using a framing streak camera captured two dimensional spontaneous luminescence images from chemical species at low temperature reaction(LTR) and high temperature reaction (HTR). Also, the combustion events were observed by high-speed direct photography, the ignition and combustion were analyzed by the combustion chamber pressure profiles.

• 오토저널
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• 제5권2호
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• pp.41-47
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• 1983

The analysis shows that the variation of maximum pressure of the cycle, rate of hear release, rate of mass burned, and combustion delay are influenced by the inlet air humidity in the spark-ignition engine. The quantitative combustion delay can be obtained from the rate of mass burned. Also, the variation of time loss and effective compression ratio with the change of inlet air humidity are dominated by the development of rate of heat release.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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• pp.177-180
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• 2015

The chemical aspects of primary reference fuel (PRF)/air mixture under RCCI conditions are investigated to provide fundamental insights into the ignition characteristics of RCCI combustion. Chemical explosive mode analysis (CEMA) is adopted to understand the ignition process of the lean PRF/air mixture by identifying controlling species and elementary reactions at different locations and times.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.2088-2093
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• 2004

Harmful elements from the exhaust gases are caused by incomplete combustion of mixture inside the engine cylinder and this abnormal combustion like misfire or partial burning is the direct cause of the air pollution and engine performance degradation. In this study, I obtain the shapes of spark, voltage and current generated when changing the experimental parameters such as grounded electrode shapes, electrode gap and the material of center electrodes. After that, I produce ignition energy by using the voltage and current and classify ignition energy into capacitive discharge energy and inductive discharge energy.

• 오토저널
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• 제14권5호
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• pp.61-68
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• 1992

Knock phenomenon is an abnormal combustion originated from autoignition of unburned gas in the end-gas region during the later stage of combustion process and it accompanys a high pitched metallic noise. Engine Knock is accompanied with a vibration of engine cylinder and when it is severe, it can cause major engine demage. Engine Knock is characterized in terms of knock crank angle, knock pressure, pressure jump and knock intensity. In this study, a 4-cylinder spark ignition engine was used for experiment and eighty consecutive cycles were analyzed statistically. The purpose of this study is to characterize spark ignition engine knock as a function of ignition timing and fuel research octane number. The result of this study can be summerized as follows. Knock occurrence angle approached TDC as ignition timing is advanced. Pressure and knock intensity gradually increased as spark timing is advanced. Mean knock occurence angle gradually approached TDC as fuel research octane number is decreased for identical spark timing. Knock intensity increased linearly as RON is decreased.

• 에너지공학
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• 제16권3호
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• pp.113-119
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• 2007

데칸에 물을 혼합하여 일정한 크기와 간격으로 유화액적배열을 형성하여 물과의 혼합비율, 액적의 수 그리고 액적 간격 등이 연소특성에 어떠한 영향을 주는가를 고온의 연소실에서 파악하였다. 각각 10%, 20%, 30%의 물을 혼합하여 유화액적을 만든 후 일정한 크기의 액적을 각각의 서스펜더에 매달아서 일정한 간격의 액적배열을 만들어 고온에서 자발화를 시켰을 때, 점화지연, 수명시간, 전연소기간 그리고 미소폭발 등의 연소특성을 비교하였다. 대기압에서 연소실의 온도를 920 K로 하고 서스펜더의 수를 3개와 5개로 하였으며 액적배열의 간격은 $3{\sim}7\;mm$ 범위에서 1 mm 간격으로 각각 실험을 수행하였다. 본 실험을 통하여 물의 혼합비율이 높을수록, 그리고 액적배열의 간격이 넓을수록 점화지연현상이 길게 나타났으며, 수명시간은 액적의 간격이 넓을수록 짧게 나타났으며 점화지연시간과 수명시간의 합인 전연소기간은 액적의 수량이 3개인 경우가 점화지연시간이 긴 관계로 5개에 비해 길게 나타남을 확인하였다.

• 대한기계학회논문집
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• 제19권8호
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• pp.2030-2038
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• 1995

In this study, three turbulent flame propagation models are compared using experimentally measured data of a 4 valves/cylinder spark-ignition engine. First two conventional models are B.K model and GESIM combustion model. The burning rates calculated from the two models are compared with the burning rates calculated from measured pressure data using the one-zone heat release analysis. GESIM combustion model predicts burning rates closer to the data acquired from the experiment in wide operating ranges than B-K model does. The third model is refined based on GESIM combustion model by including the effect of flame stretch, turbulent length scale band pass filter and a variable that considers flame size and the area of flame contacting the cylinder wall surface. The refined combustion model predicts burning rates closer to experimental results than GESIM combustion model does. Also, the refined combustion model predicts flame radius close to the experimental result measured by using optical fiber technique.

• International Journal of Automotive Technology
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• 제5권3호
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• pp.195-200
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• 2004

This paper is concerned with the Homogeneous Charge Compression Ignition (HCCI) engine as a new concept in engines and a power source for future automotive applications. Essentially a combination of spark ignition and compression ignition engines, the HCCI engine exhibits low NOx and Particulate Matter (PM) emissions as well as high efficiency under part load. The objective of this research is to determine the effects of Exhaust Gas Recirculation (EGR) rate on the combustion processes of HCCI. For this purpose, a 4-cylinder, compression ignition engine was converted into a HCCI engine, and a heating device was installed to raise the temperature of the intake air and also to make it more consistent. In addition, a pressure sensor was inserted into each of the cylinders to investigate the differences in characteristics among the cylinders.

• 대한기계학회논문집B
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• 제39권2호
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• pp.135-146
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• 2015

본 논문은 대형 상용기관을 모사한 정적연소실에서 매립지 가스의 연소 특성에 대한 복수의 논문 중 네 번째로, 열 발생 특성과 가시화 결과를 관찰하여 토치 연소의 특징을 논의하였다. 분석 결과 토치 연소는 주 연소실에 형성된 화염 면을 토치에서 분출되는 가스가 가속시킴으로 연소를 촉진한다. 이때 오리피스 직경이 4mm일 때는 토치에서 고온의 가스가 분출되며, 6mm 이상에서는 토치에서 형성된 화염이 직접 오리피스를 통과한다. 또한 메탄 분율, 토치 체적 그리고 오리피스 크기가 상호 연관적으로 작용하여 다양한 연소 형태를 야기하고 이에 따라 토치 연소의 효과가 매우 다르게 나타난다. 마지막으로 실물기관에서 연소 과정의 일관성을 보장하는 적절한 토치의 조건은 6mm 이상의 오리피스 직경과 0.15 이하의 오리피스 면적비를 동시에 만족시키는 것이다.

• 대한기계학회논문집B
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• 제21권12호
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• pp.1647-1655
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• 1997

The cyclic variations can be characterized by the variations in different type of parameters. These parameters may be grouped into four main categories: pressure-related parameters, combustion-related parameters, flame front-related parameters, and exhaust gas-related parameters. One of the resultant effects of the cycle-by-cycle variation in the combustion process, which is the most important with regard to the engine performance characteristics, is the cycle-by-cycle variation in IMEP. This paper uses the repetitive discharge igniter, which can change the ignition energy easily, to study on idle stability in a spark ignition engine. From this device, the 6 number of spark and 0.20 ms spark interval, it is very available for the idle stability.