• Journal of ILASS-Korea
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• v.13 no.2
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• pp.65-72
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• 2008

It is recognized that alternative fuel such as dimethyl ether (DME) has better combustion polluting characteristics than diesel fuel, even though the cetane number of DME is almost the same as that of diesel. Characteristics of DME spray were observed experimentally under various ambient conditions using a constant volume chamber and a common-rail injection system. N-dodecane and LPG fuel sprays were also observed under same conditions of DME spray. Using spray images from backlight scattering and Mie scattering, characteristics of fuel sprays such as penetration and spray volume were visualized and quantitatively measured. The measurements showed that the penetration of early period decreased remarkably, because evaporation of alternative fuels became prosperous by the influence of flash boiling phenomenon under the condition of the low temperature and pressure compared with n-dodecane. The penetration of DME and LPG spray received the influence of temperature more largely in comparison with low density, because the specific surface area increased by atomizing in high density.

• 한국연소학회:학술대회논문집
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• 2006.04a
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• pp.121-127
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• 2006

It has become inevitable to search for alternative fuels due to severe energy crisis these days. Use of alternative fuels, which are typically of lower quality, tends to increase environmental pollution, including formation of nitrogen oxides (NOx). In this paper performance of vacuum residue has been investigated experimentally as well as numerically in typical operating conditions of a furnace. Heat release reaction is modeled as sequential steps of devolatilization, simplified gas phase reaction and char oxidation as that for pulverized coal. Thermal and fuel NOx are predicted by conditional estimation of elementary reaction rates and are compared against measured experimental data. On the overall reasonable agreement is achieved for spatial distributions of major species, temperature and NOx for all test cases.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.2
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• pp.16-21
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• 2003

Natural gas is one of the promising alternative fuels because of the abundant deposits and the cleanness of emission gas. It can be used in conventional gasoline engine without major modification. Natural gas has some advantages than gasoline i.e. the high octane number, good mixing condition because of gas and wide inflamable limit. In the present study, a $1.8{\ell}$ conventional gasoline engine is modified for using the CNG as a fuel instead of gasoline. Performance and emission characteristics are compared between gasoline and CNG with 4 cylinder SI Engine which is controlled by programable ECU. Parameters of experimentation are equivalence ratio, spark timing and fuels. We analyzed the combustion characteristics of the engine using the cylinder pressure i.e. ignition delay, combustion duration and cycle variation. As a result, CNG engine shows lower exhaust emissions but brake torque is slightly reduced compared to gasoline engine. Overall combustion duration is longer than that of gasoline because of lower burning speed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.1
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• pp.77-84
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• 1994

The oil crises in 1973 and 1978 stimulated the alternative fuel research activities in many countries around the world. Among the alternative fuels, methanol is one of the highest potential fuels for transportation. Methanol has been considered for use as automotive fuel, but it has a defect of the great latent vaporization heat. Therefore, authors have made the fuel vaporizing device in order to eliminate the fuel film flow heating the mixture. This paper presents a study on the characteristics of vaporization, engine performance, and emission which result from using the fuel vaporizing device.

• International Journal of Automotive Technology
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• v.8 no.2
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• pp.179-184
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• 2007

In this study, the potential use of oxygenated fuels such as ethylene glycol mono-normal butyl ether (EGBE) was investigated in an attempt to reduce the emission of exhaust smoke from diesel engines. Effects of the combustion method on exhaust emission of DI and IDI diesel engines were also examined. Since EGBE is composed of approximately 27.1% oxygen, this is one of several potential oxygenated fuels that could reduce the smoke content of exhaust gas. EGBE blended fuels have been proven to reduce smoke emission remarkably compared to the conventional commercial fuels. The test was conducted with single and four cylinder, four stroke, DI and IDI diesel engines. The study showed that a simultaneous reduction of smoke and NOx emission could be achieved by the combination of oxygenated blend fuels and the cooled EGR method in both DI and IDI diesel engines. It was also found that a reduction rate of exhaust emission in a DI engine was larger than an IDI diesel engine.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.11a
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• pp.235-236
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• 2018

• Computational Structural Engineering
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• v.35 no.3
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• pp.19-27
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• 2022

• Magazine of RCR
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• v.19 no.2
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• pp.55-61
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• 2024

• Journal of the Korean Institute of Gas
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• v.19 no.6
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• pp.34-39
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• 2015

Recently, most of the energy consumed in vehicle is derived from fossil fuels. For this reason, the demand for clean, renewable and affordable alternative energy is forcing the automotive industry to look beyond the conventional fossil fuels. Natural gas represents today a promising alternative to conventional fuels for vehicles propulsion, because it is characterized by a relatively low cost, better geopolitical distribution than oil, lower environmental impact, higher octane number and a higher self ignition temperature. Above all, CNG is an environmentally clean alternative to the existing spark ignition engines with the advantages of minimum change. In this study was installed bi-fuel system that a conventional 2 liters gasoline engine was modified to run on natural gas by a gas injection system. Experiments were mainly carried on the optimization of an ECU control strategy affecting the emission characteristics of CNG/Gasoline bi-fule vehicle. The test results shown that CO2 emission in bi-fuel mode was reduced 16% compared to gasoline fuel in the NEDC mode. Also the amount of CO and HC emissions in bi-fuel and gasoline modes were found to equality. But Compared to gasoline, the bi-fuel mode resulted in higher NOx emissions.

• Journal of ILASS-Korea
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• v.20 no.2
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• pp.88-94
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• 2015

Recently, exhaust gas regulation has been gradually strengthened due to depletion of fossil fuels and environmental problem like a global warming. Due to this global problem, the demand for eco-friendly vehicle development is rapidly increasing. A clean diesel vehicle is considered as a realistic alternative. The common-rail fuel injection system, which is the key technology of the clean diesel vehicle, has adopted injection strategies such as high pressure injection, multiple injection for better atomization of the fuel. In addition, the emission regulations in the future is expected to be more stringent, which a conventional engine is difficult to deal with. One of the way for actively proceeding is the study of alternative fuels. Among them, the bio-diesel has been attracted as an alternative of diesel. So, in this study, spray characteristics of bio-diesel was analyzed in the common-rail fuel injection system with three injectors driven by different operating mechanism.