• 한국자동차공학회논문집
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• 제13권2호
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• pp.44-51
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• 2005

According to the increasing concern on the global environment, the $CO_2$ regulation has been discussed including automobile emission regulation. In order to cope with this rapid changing circumstances, the development of an ultra low emission and super fuel economy automobile is essential. Direct injection LPG engine is the one of the possible future engine to maximize the engine efficiency. This experimental study for the development of direct injection LPG engine technology is promoted with two parts; spray characteristics of high pressure swirl injector, and performance characteristics of direct injection LPG engine. Engine characteristics according to the fuel was analyzed in order to establish stratified combustion technology for LPG engine by using the DISI engine. In the engine experiment, control system was manufactured for gasoline and LPG fuel. The engine was modified 2,000 cc GDI engine (fuel supply device, fuel injection device). Through this experiment, engine operating condition, engine speed and spark timing (MBT), fuel injection position, and fuel rate were investigated.

• 한국자동차공학회논문집
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• 제2권5호
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• pp.30-40
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• 1994

The direct-injection stratified-charge engine has the advantages of higher thermal efficiency and less CO and $NO_x$ emission levels than conventional spark ignition engines. However, its actual utilization is prevented by high unburned hydrocarbon emission levels during light-load operations. In this paper, fundamental studies were carried out using a pancake type constant volume bomb. The effects of intensification of local premixing by tangential and radial fuel injection were examined experimentally. Unburned hydrocarbon emission levels with radial fuel injection were shown to be lower than those of tangential fuel injection cases. The stratification and mixing process of fuel jet and combustion process were observed by schlieren photography.

• 한국자동차공학회논문집
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• 제7권5호
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• pp.22-30
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• 1999

Optimization of in-cylinder flow is regarded as one of the most important factors to realize stable stratified charge combustion in a Spark-ignited Direct Injection(SDI) engine. Therefore, Computational Fluid Dynamic(CFD) simulation technique were used to clarify the characteristics of in-cylinder flow of a SDI engine with top entry intake port. Also, CFD results were compared to experimental results using Laser Doppler Velocimetry(LDV), Particle Image Velocimetry(PIV) and good validations were met. As the results reverse tumble flow generated during intake process was preserved by configuration of curved piston while base and reverse tumbles were diminished at the end of compression stroke in case of flat top piston. In addition, it will be needed to optimize the fuel mixture distribution based on these results.

• 한국가스학회지
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• 제20권1호
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• pp.52-61
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• 2016

액화석유가스는 환경 친화적이며 에너지 효율성과 출력성능이 뛰어나 실용성이 높고, 경쟁연료에 비해 가격 경쟁력이 우수하기 때문에 촉망받는 대체연료 중 하나로 간주된다. 스파크점화 엔진에서 직분식 기술은 엔진 체적효율을 눈에 띄게 증가시키며, 상대적으로 더 높은 연소효율이 가능한 성층급기를 이용해 엔진을 작동시킨다. 본 연구에서는 가솔린직접분사 엔진의 원리를 적용하여 가시화 시스템을 장착한 연소실을 설계하였다. 이를 통해 스파크점화직분식 LPG의 점화성과 화염전파 과정을 디지털 방식으로 기록하고 분석하였다. 이러한 연구의 결과는 스파크점화직분식 LPG 엔진의 설계 및 최적화를 위한 광범위한 기초 자료로서 기여하고자 한다.

• 한국자동차공학회논문집
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• 제1권2호
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• pp.17-26
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• 1993

As fundamental step to find the suitable compression ratio of hydrogen fueled engine, performance and combustion characteristics of that engine were analyzed. Qualitative characteristics of the hydrogen fueled engine were similar to that of the gasoline engine, and it was also found that knock limit compression ratio of the hydrogen fueled engine was higher than that of the gasoline engine.