• 한국안전학회지
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• 제8권4호
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• pp.3-15
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• 1993

A multi-cylinder four cycle spark ignition engine equipped with on exhaust gas recirculation(EGR) system to reduce nitric oxide emission and to improve fuel consumption rate has been comprehensively simulated In a computer program including intake and exhaust manifolds. To achieve these goals, this program was tested against experiments performed on a standard production four cylinder four cycle gasoline engine with EGR system. As EGR rate Increased, the maximum temperature of combustion chamber and NO omission concentration decreased under each driving condition. But the emission concentration of CO didn't change much through whole district in spite of the increase of EGR rate. Fuel consumption rate improved under each driving condition according to the increased of EGR rate until 10 percent EGR rate. Therefore the degree of EGR depend not only on the NO emission but also on the economy and the engine performance criteria of the engine.

• 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.

• 한국산업보건학회지
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• 제8권2호
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• pp.289-295
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• 1998

Used gasoline engine oils(UGEO) are carcinogenic in long term studies and capable of increasing the number of carcinogen-DNA adducts in short term studies when dermally applied to mice. The carcinogenic risk of UGEO has been attributed to the concentration of polycyclic aromatic hydrocarbons(PAH) which accumulate in the lubricating system during the combustion of gasoline. When dermally exposed to UGEO, the use of hand cleanser was commonly recommended for removing it. But generally workers who dermally exposed oils, use kerosene as cleaner which make skin trouble. During this study, female mice aged 4-6 weeks were utilized to evaluate the efficiency of kerosene, as solvent-based cleanser, following dermal exposure to UGEO. DNA adduct were detected at skin and lung tissues by using the $^{32}P$-postlabeling method. Washing with cleansers were done at two different interval times following dermal application of UGEO. The total DNA adducts in skin and lung tissues were statistically significantly increased in positive control groups, and of which the total adduct level in skin tissues was statistically significant higher than those in lung tissues(p=0.005). When washing kerosene, the DNA adduct level in skin tissues was statistically significantly decreased(p=0.0001). But DNA adducts in lung tissue was statistically increased(p=0.0039), and that washed at 8hr post exposure was more severly increase(p<0.05). The slope of regression between DNA adducts of lung between skin tissues was 1.0802. In conclusion, skin cleaning with kerosene facilitates passage of carcinogens to the lungs of animals dermally treated with used gasoline engine oils(UGEO).

• 한국가스학회지
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• 제19권6호
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• pp.1-7
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• 2015

지구온난화와 화석연료 고갈 문제의 해결을 위하여 대체 연료 개발에 많은 노력을 하고 있다. 암모니아(NH3)는 수소와 마찬가지로 탄소를 포함하고 있지 않으면서 대표적인 수소 캐리어이다. 또한, 상온에서 0.6 MPa 정도의 압력을 가하면 액상을 유지할 수 있어 LPG 충전인프라를 그대로 사용가능한 장점이 있다. 본 연구는 암모니아를 가솔린과 함께 혼소시켰으며, 혼소 비율에 따른 엔진 성능을 비교하였다. 암모니아와 가솔린의 혼소를 위하여 가솔린 인젝터와 암모니아용 인젝터를 각각 사용하였으며, 암모니아는 액상으로 분사시켰다. 암모니아-가솔린 혼소 엔진의 최대 장점은 가솔린 대체량에 비례하여 이산화탄소 배출량을 크 게 감소시킬 수 있다는 것이다. 하지만 암모니아-가솔린 혼소율에 따라 연소가 불안정한 구간이 있었으며, 암모니아 혼소 비율 0.7 이상에서는 연소 불안정성 증가로 인해 토크와 NOx 배출량이 감소하고, THC 배출량이 급증하였다.

• Tribology and Lubricants
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• 제28권4호
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• pp.178-183
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• 2012

The fuel system of a vehicle is a very important compotent, as it provides the firing resources to the combustion chamber of the engine. However, improper operation of the system can generate bad condition or start-off during engine revolution. This study analyzed several examples of failure that had originated in the field. In the first example, the driver operated a vehicle containing both gasoline and LPG in the fuel tank, but the gasoline fuel remained unused for a few months. Therefore the fuel pump was clogged because of gasoline congelation. The second example, dealt with fuel leakage that occurred from the slightly torn O-ring connecting the fuel lines. The third example, pertained to engine damage and power-down owing to the usage of proor-quality fuel and ingredient. Therefore, it is necessary to take adequate measures to prevent the failure of the fuel system of vehicle.

• 한국음향학회지
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• 제37권4호
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• pp.242-247
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• 2018

지속적으로 강화되는 배기가스 및 연비 규제에 대응하기 위해 자동차 업계에서는 다양한 노력을 하고 있다. 하지만 이로 인해 NVH(Noise, Vibration, and Harshness) 성능이 악화되는 경우들이 많이 발생하고 있다. 사례로 가솔린 엔진의 고압 펌프 소음 및 MPI(Multi-Point Injection)와 GDI(Gasoline Direct Injection)의 듀얼 분사로 인한 가속 천이 소음, 가솔린 터보차저 소음, 디젤 엔진에서의 분사변수 캘리브레이션으로 인해 악화되는 연소음에 대한 원인 및 개선방향을 제시하였다. 이러한 소음들은 고주파 소음으로 운전자에게 거친 청감을 유발하기 때문에 적절한 NVH 대책으로 저감시키는 노력이 반드시 필요하다.

• 한국기계가공학회지
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• 제13권4호
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• pp.69-74
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• 2014

A waste gate valve (WGV) assembly for a gasoline turbocharger is typically manufactured by means of precision casting. In this study, however, it was newly manufactured in a more innovative way, metal injection molding (MIM) using Inconel 713C alloy, and its performance was tested in a 1.6L direct injection gasoline engine by a thermal shock durability test that lasted 300 hours, after which the results were compared to those of a precision-cast WGV assembly with regard to the engine intake boost pressure, turbine wheel speed, and transient intake pressure. It was found that the two WGV assemblies showed similar performance levels throughout the durability test.

• Journal of Advanced Marine Engineering and Technology
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• 제28권3호
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• pp.475-481
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• 2004

Recently it is strongly required on lower fuel consumption. lower exhaust emission, higher engine performance. and social demands in a spark ignition gasoline engine. In this study. the experimental engine used at test. it has been modified the lean burn gasoline engine. and used the programmable engine management system, and connected the controller circuit which is designed for the engine control. At the parametric study of the engine experiment, it has been controlled with fuel injection, ignition timing. swirl mode, equivalence ratio engine dynamometer load and speed as the important factors governing the engine performance adaptively. It has been found the combustion characteristics to overcome the hysteresis phenomena between normal and lean air-fuel mixing ranges. by mean of the look-up table set up the mapping values. at the optimum conditions during the engine operation. As the result, it is found that the strength of the swirl flow with the variation of engine speed and load is effective on combustion characteristics to reduce the bandwidth of the hysteresis regions. The results show that mass fraction burned and heat release rate pattern with crank angle are reduced much rather, and brake specific fuel consumption is also reduced simultaneously.

• 윤활유협회보
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• 88호
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• pp.8-27
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• 1998

• 한국자동차공학회논문집
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• 제24권2호
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• pp.232-241
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• 2016

The turbocharger, to decrease the harmful exhaust gas(CO, HC and etc.) and $CO_2$ emission as well as the increase of the engine output, would be an useful method for engine downsizing. Therefore the thermal endurance of turbine blade, the lubrication of turbine shaft and the engine knock according to the supercharge of the inlet air, had been studied. And there had been much progress in these research tasks to be achieved a breakthrough. But a study on the built-in WGV of a gasoline engine for a passenger car which may effect on the engine performance, is few. In this paper, the effect of the embedded WGV on the engine performance was performed through the endurance test, which was conducted more than 300 hrs using the 4 stroke, 1998 cc, water-cooled engine. To sum up the major results, there were an abrasion in the area of the WGV head edge and the thermal deformation on the WGV head face, These phenomena led to reducing the boost pressure which caused the reduction in the volumetric efficiency of the engine. It resulted in decreasing the engine power gradually during the life cycle of the embedded WGV.