• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.1-7
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• 2015

An ammonia fuel system is developed and applied to a 1 liter gasoline engine to use ammonia as primary fuel. Ammonia is injected separately into the intake manifold in liquid phase while gasoline is also injected as secondary fuel. As ammonia burns 1/6 time slower than gasoline, the spark ignition is needed to be advanced to have better combustion phasing. The test engine showed quite high variation in the power output to lead high increase in THC emission with large amount of ammonia, that is, higher than 0.7 ammonia-gasoline fuel ratios.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.2
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• pp.137-143
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• 2012

Currently, in order to meet the reinforced emissions regulations for harmful exhaust gas including carbon dioxide ($CO_2$) as a greenhouse gas, technologies for reducing $CO_2$ emission and fuel consumption are being developed. Gasoline direct injection (GDI) systems have the advantage of improved fuel economy and higher power output than port fuel injection gasoline engine systems. The aim of this study is to examine the performance and emission characteristics of a lean burn GDI engine equipped with spray-guided-type combustion system. Stable lean combustion was achieved with a late fuel injection strategy under a constant operating condition. Further improvement in specific fuel consumption is possible with the introduction of multiple fuel injection strategies, which also increases hydrocarbon (HC) and nitrogen oxide ($NO_x$) emissions and decreases carbon monoxide (CO) emission.

• Aerospace Engineering and Technology
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• v.4 no.1
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• pp.260-267
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• 2005

An electronic spark ignition unit has been developed for gasoline for small UAV. The unit is programmable to adjust the optimal ignition advance angle in accordance with rpm and intake pressure. Initial advance angle and the position of Hall sensor on the engine can be set from PC via serial interface. The results are expected to be valuable core technology of powerplants in developing small UAV's.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.3
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• pp.358-364
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• 2016

The combustion and exhaust emission characteristics in a spark ignition (SI) engine with various test fuels (bioethanol - gasoline blends) and air-fuel ratio were investigated in this research. To investigate the influence of the excess air ratio and ethanol blends on the combustion characteristics such as the cylinder pressure, rate of heat release (ROHR), and fuel consumption rate were analyzed. In addition, the reduction effects of exhaust emissions such as carbon monoxide (CO), unburned hydrocarbon (HC), and oxides of nitrogen (NOx) were compared with those of neat gasoline fuel under the various excess-air ratios. The results showed that the peak combustion pressures and the ROHR of bioethanol fuel cases were slightly higher than those of gasoline fuel at all test ranges and fuel ratio. As compared with gasoline fuel (G100) at each given excess air ratio, BSFC of bio-ethanol was increased. The CO, HC, NOx emissions of bio-ethanol blends were lower than those of gasoline fuel under overall experimental conditions.

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.2
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• pp.128-135
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• 2008

EGR(exhaust gas recirculation) is considered as a most effective method to reduce the NOx emissions. But high EGR tolerance is always pursued not only for its advantages of the pumping loss reduction and fuel economy benefit in Gasoline-Hybrid engine. However, the occurrence of excessive cyclic variation with high EGR normally prevents substantial fuel economy improvements from being achieved in practice. Therefore, the optimum EGR rate should be carefully determined in order to achieve low fuel consumption and low exhaust emission. In this study, 2 liters gasoline engine with E-EGR system was used to investigate the effects of EGR on fuel efficiency, combustion stability, engine performance and exhaust emissions. With optimal EGR rates, the fuel consumption was improved by 4%. This improvement was achieved while a reduction in NOx emissions of 75% was accomplished. Increase of EGR gas temperature causes the charge air temperature to affect the knock phenomenon and moreover, the EGR valve lift changes for the same control signal.

• Journal of the korean Society of Automotive Engineers
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• v.25 no.6
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• pp.19-24
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• 2003

• Transactions of the Korean Society of Automotive Engineers
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• v.16 no.4
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• pp.143-150
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• 2008

EGR(exhaust gas recirculation) is an attractive means of improving the fuel economy of spark ignition engines, as it offers the benefits of charge dilution (lower pumping and cooling losses) while allowing stoichiometric fuelling to be retained for applications using the three-way catalysts. However, the occurrence of excessive cyclic variation with high EGR normally prevents substantial fuel economy improvements from being achieved in practice. Therefore, the optimum EGR rate in Gasoline-Hybrid engine should be carefully determined in order to achieve low fuel consumption and low exhaust emission. In this study, 2 liters gasoline engine with E-EGR system was used to investigate the effects of EGR on fuel economy, combustion stability, engine performance and exhaust emissions. EGR tolerance with load variation was found to be more sensitive than with rpm variation. With optimal EGR rates, the fuel consumption was improved by 5.5% while a combustion stability was guaranteed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.2
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• pp.516-521
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• 2012

Computational simulation has been conducted to analyze the oil separation performance of gasoline engine oil separators. Two models are compared to select a proper oil separator for the engine. To analyze oil separation characteristics, d50 and separation efficiency have been calculated for each separator. As a result, model A shows excellent d50 and separation efficiency, and model B shows good pressure-drop characteristics. Model B is recommended for the general gasoline engine with low crank-case pressure and low oil consumption. Model A is recommended for the engine with high crank-case pressure and high oil consumption, especially equipped with special exhaust gas treatment system, that is critical to the oil contamination.

• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.3
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• pp.46-54
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• 1993

In order to develop a fuel-efficient gasoline engine oil, an experimental study was conducted using an engine dynamometer, a passenger car and the SRV machine. Oil samples with different viscosity were prepared by adding several friction modifiers to select the best one and also to investigate the effect of the viscosity grade. From the study, we have developed engine oils which result in good fuel economy. The viscosity grade of 7.5W/30 was best among the oils investigated with respect to fuel economy and a fatty amine type friction modifier had the good fuel-economy property.

• Journal of the KSME
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• v.33 no.12
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• pp.1052-1062
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• 1993

지금까지 엔진내의 연소현상에 관한 많은 문헌들이 보고되고 있으나, 주로 계측기술에 관한 전 반적인 소개 내용이 많으며, 실제 엔진에 대한 적용 현황과 적용시 발생하는 문제점 및 해결책 등에 대한 보고는 많지않은 실정이다. 이 글에서는 필자가 경험한 계측과 가시화 기술을 중심으 로 엔진내의 연소현상 해석에 적용되는 최근의 광응용 계측기술 및 개발 동향을 소개하고자 한다.