• Transactions of the Korean Society of Mechanical Engineers B
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• v.22 no.11
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• pp.1530-1537
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• 1998

Mixture formation is one of the significant factors to improve combustion performance of an spark ignition engine. This is affected by spray and atomization characteristics of injector. In the case of EGI system, air-fuel mixing period is so short that a lot of fuel-film and liquid-fuel flow into cylinder. Since this fuel-film is not burnt perfectly in cylinder, it is exhausted in the form of HC emission. In this paper, three measurement techniques were utilized to measure spray characteristics and the amount of fuel-film in the cylinder. At first, PMAS was used to measure the spray characteristics such as size distributions, SMD, and spray angle. Secondly the amount and distribution of fuel-film which flow into through intake valve could be measured quantitatively using the fuel-film measuring device. And lastly, by optical fiber type spark plug used to detect the diffusion flame, the amount of unburned HC was measured. As the result of these experiments, the information of optimal spray characteristics and injection condition to minimize fuel-film could be built up.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.7
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• pp.609-615
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• 2015

In this study, the combustion and exhaust emission characteristics in a gasoline direct injection engine with variations of the bio-ethanol-gasoline blending ratio and the excess air factor were investigated. To investigate the effects of the excess air factor and the bio-ethanol blends with gasoline, combustion characteristics such as the in-cylinder combustion pressure, rate of heat release (ROHR), and the fuel consumption rate were analyzed. The reduction of exhaust emissions such as carbon monoxide (CO), unburned hydrocarbon (HC), and nitrogen oxides ($NO_x$) were compared with those of gasoline fuel with various excess air factors. The results showed that the peak combustion pressure and ROHR of bio-ethanol blends were slightly higher and were increased as bio-ethanol blending ratio is increased. Brake specific fuel consumption increased for a higher bio-ethanol blending ratio. The exhaust emissions decreased as the bio-ethanol blending ratio increased under all experimental conditions. The exhaust emissions of bio-ethanol fuels were lower than those of gasoline.

• Journal of Power System Engineering
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• v.6 no.3
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• pp.11-16
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• 2002

This paper describes the power performance and emission characteristics of the high speed direct injection diesel engine (2.9 litter displacements) driven by soybean oil asknown a bio diesel fuel. The results were compared to diesel fuel with blending bio diesel fuels. The soybean bio diesel fuel was added in the diesel fuel in concentration varying from 25% to 75% volume rates. We measured the emissions according to ECE 13 mode and full load, fixedengine speed. When the 25% bio diesel fuel was used, NOx emission at the ECE 13 mode test slightly decreased compared with diesel base engine. Over engine speed of 2000 rpm, the level of unburned hydrocarbon(HC) and carbon monoxide(CO) were the same to the diesel engine. Smoke emission decreased asthe blending bio diesel fuel rate increased.

• Journal of Advanced Marine Engineering and Technology
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• v.24 no.5
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• pp.111-118
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• 2000

Experimental studies were performed to understand the flow characteristics in the exhaust system and improve the THC emission characteristics by optimizing the flow in the exhaust manifold and CCC in a SI engine. For this purpose, the flow characteristics in the exhaust systems with two types of exhaust manifolds(STD and New Type) were measured by using LDV technique under various engine condition. It was found that the flow characteristics in the New Type exhaust manifold was more desirable in a view point of heat loss reduction from the exhaust gases. The vehicle emission tests showed that the THC emission in the New Type exhaust manifold was decreased by 12%.

• 한국연소학회:학술대회논문집
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• 2002.11a
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• pp.89-95
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• 2002

A hybrid De- NOx technique of non-thermal plasma and $NH_3$ SCR process has been investigated to remove NOx from 300 hp marine engine exhaust under the low temperature conditions, i.e. $100-200^{\circ}C$. Fundamental investigation with Diesel-like simulant gas was also conducted. The performance of the present technique has been demonstrated by treating real diesel exhaust gases, in which high contents of soot, water vapor, $SO_2$, NOx, and unburned HC are included. Detailed engineering data for evaluating the feasibility of the technique are provided in the present investigation.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.1
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• pp.37-43
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• 2010

The purpose of this paper is to investigate the effect of air-fuel ratio on the combustion and emissions characteristics of spark ignition (SI) gasoline engine fueled with bio-ethanol. A 1.6L SI engine with 4 cylinders was tested on EC dynamometer. In addition, lambda sensor and lambda meter were connected with universal ECU to control the lambda value which is varied from 0.7 to 1.3. The engine performance and combustion characteristics of bio-ethanol fuel were compared to those obtained by pure gasoline. Furthermore, the exhaust emissions such as carbon monoxide (CO), unburned hydrocarbon (HC), oxides of nitrogen ($NO_X$) and carbon dioxide ($CO_2$) were measured by emission analyzers. The results showed that the brake torque and cylinder pressure of bio-ethanol fuel were slightly higher than those of gasoline fuel. Brake specific fuel consumption (BSFC) of bio-ethanol was increased while brake specific energy consumption (BSEC) was decreased. The exhaust emissions of bio-ethanol fuel were lower than those of gasoline fuel under overall experimental conditions. However, the specific emission characteristics of the engine with bio-ethanol fuel were influenced by air-fuel ratio.

• Journal of ILASS-Korea
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• v.17 no.1
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• pp.1-8
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• 2012

This study described the effect of the multiple injections and diesel-ethanol on the NVH, combustion and emission characteristics of 4 cylinder common rail diesel engine. In order to investigate the influence of diesel-ethanol blended fuel in a light-duty common rail diesel engine, the injection strategy was varied with pilot injection, double pilot injections, and one main injection at various operating conditions. The results showed that diesel-ethanol blended fuel had longer ignition delay than that of the ultra low diesel fuel(ULSD). Also, in the case of multiple injections, the combustion pressure is increased smoothly near the TDC and the NVH are decreased. In the emission characteristics, diesel-ethanol blended fuel produced lower indicated specific nitrogen oxides(IS-NOX) and indicated specific Soot(IS-soot) emissions, however, indicated specific unburned hydrocarbon(IS-HC) and indicated specific carbon monoxide(IS-CO) emissions are slightly increased.

• Transactions of the Korean Society of Automotive Engineers
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• v.19 no.1
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• pp.82-88
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• 2011

Lean combustion and exhaust emission characteristics in a ethanol fueled spark-ignited engine according to ethanol-gasoline fuel blending ratio were investigated. The test engine was $1591cm^3$ and 10.5 of compression ratio SI engine with 4 cylinders. In addition, lambda sensor system was connected with universal ECU to control the lambda value which is varied from 1.0 to 1.5. The engine performance and lean combustion characteristics such as brake torque, cylinder pressure and rate of heat release were investigated according to ethanol-gasoline fuel blending ratio. Furthermore, the exhaust emissions such as carbon monoxide (CO), unburned hydrocarbon (HC), nitrogen oxides ($NO_x$) and carbon dioxide ($CO_2$) were measured by emission analyzers. The results showed that the brake torque, cylinder pressure and the stability of engine operation were increased as ethanol blending ratio is increased. Brake specific fuel consumption (BSFC) was increased in higher ethanol blending ratio while brake specific energy consumption (BSEC) was decreased in higher ethanol blending ratio. The exhaust emissions were decreased as ethanol blending ratio is increased under overall experimental conditions, however, some specific exhaust emission characteristics were mainly influenced by lambda value and ethanol-gasoline fuel blending ratio.