• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.1
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• pp.55-63
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• 2003

In a diesel engine, air-fuel mixture formation and ignition delay period have great influence on the performance of engine. Their main factors are combustion chamber shape, fuel injection system. air volume, air flow and so on. So, the combustion process in the cylinder is complex because of many factors which have direct and indirect effects on it. In this study, we take into consideration of scavenging pressure and scavenging temperature that are hewn as the main factor to the combustion process of two-stroke D.1. diesel engine. It is taken a picture of the combustion flame process for combustion chamber of re-entrant type and cylindrical type. So, it is applied to the basis data of combustion chamber design from an image analysis.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.283-284
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• 2014

• Journal of Biosystems Engineering
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• v.17 no.1
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• pp.5-17
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• 1992

To develop an analytic method of combustion characteristics in a small sized and single cylinder type diesel engine for a power tiller, 1) the theoritical analysis of combustion gas in engine cylinder was performed based on thermoscience and 2) the computer program which could be used to calculate those values of the apparent burning rate, the heat loss, the gas temperature and the fuel-air equivalence ratio with the experimental cylinder pressure data, was developed. This method would provide the practical and quantative data for the diesel combustion process. Through the use of this method, following details would be obtained: 1) the application in the modeling of combustion process without detail knowledeg of combustion process, 2) the basis for the complete modeling of diesel engine, and 3) the basic information for the design of combustion chamber by the prediction of engine performance.

• Journal of ILASS-Korea
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• v.3 no.3
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• pp.23-32
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• 1998

The effect of reentrant type bowl geometry on combustion characteristics was investigated in a D.I. diesel engine. The main factor was the aspect ratio (Bowl Diameter / Bowl Depth) of bowl of combustion chamber, and the cylinder pressure, engine performance and emissions of the engine using the 4 kinds of the combustion chamber were meadured. Also, the combustion characteristics compared of the experimented and the calculated values which is used by the Hiroyasu's combustion model. The results are as follows; The effect of $d_c/H$ on ignition delay period are small. The smoke is corerelated to the heat release of the premixed and the diffusion combustion, i.g, the smoke decreased by decreasing the premixed combustion or increasing the diffusion combustion on cumulative heat release. The premixed combustion process has more effect than the diffusion combustion on smoke. The formal tendency of $d_c/H$ on engine performance has not appear.

• 한국연소학회:학술대회논문집
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• 2002.06a
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• pp.33-38
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• 2002

An optical single cylinder diesel engine equipped with a common-rail injection system has been built to investigate diesel combustion and emission characteristics. Three optical widows (piston crown quartz for bottom view of the cylinder, upper piston quartz for allowing laser sheet and liner quartz for side view) have been placed in the optical engine to visualize spray characteristics and combustion process inside the cylinder. Before doing further research using various optical diagnostics with the optical engine, fundamental combustion experiments and flame visualization incorporating a high speed motion analyser have been carried out with a wide range of engine operating conditions.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.1
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• pp.10-16
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• 2004

The Homogeneous Charge Compression Ignition (HCCI) engine has advantage for reducing the NOx and P.M. simultaneously. Therefore, HCCI engine is receiving attention as a low emission diesel engine concept. This study was carried out to investigate the characteristics of combustion and exhaust emission for operating conditions in a direct injection type of HCCI engines such as supercharged and naturally aspirated using diesel fuel and additive. From the experimental result, we found that cool flame was always appeared and also it was difficult to control combustion characteristics by changing the injection timing in HCCI. In addition, at the lean air-fuel ratio and high speed range, it was observed that charging air pressure, additive or increasing intake air temperature is effective to increase combustion performance and reduce exhaust emission. We concluded that chemical reaction by the increasing intake air temperature or additive without physical improvement has limitation for reduction of exhaust emission.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.2
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• pp.252-258
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• 2009

Engine bench tests has been done on a common-rail diesel engine with bio-diesel fuel to study effects of B100 and B20 on output power, fuel consumption and emissions. Test results show that B100 and B20 could reduce PM, HC, CO emission and smoke, but power decrease, fuel consumption increase and NOx increase obviously, B100 reduce PM and DS with $50%{\sim}70%$ and $80%{\sim}85%$ compared with diesel fuel, while B20 reduce PM and DS with $25%{\sim}35%$ and $30%{\sim}40%$. NOx of B100 and B20 increase $5%{\sim}20%$ compare to diesel.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.12
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• pp.1756-1762
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• 2002

To effectively meet current regulations on the exhaust emissions of diesel engine required to control the deterioration of air pollution in the whole world, this study is to investigate the effects of water induction through the air intake system on the characteristics of combustion and exhaust emissions in IDI diesel engine. A method fur supplying water through the air intake system to reduce the exhaust emissions has been considered with other methods such as water introduction in the form of water-in-fuel emulsion or water injection directly into the combustion chamber, but it has not been studied about the effects of water on the combustion concepts and the characteristics of exhaust emissions in detail until now. In this study, the formation of NOx was significantly suppressed by decreasing the gas peak temperature during the initial combustion process because the water play a role as a heat sink during evaporating in the combustion chamber, but the smoke was slightly increased by increasing water amount.

• Journal of ILASS-Korea
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• v.1 no.4
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• pp.54-62
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• 1996

Effect of reentrant type bowl geometry on combustion characteristics was investigated in a D.1.diesel engine. The main factor was the aspect ratio (Bowl Diameter/Bowl Depth) of bowl of combustion chamber, and the measured data include the cylinder pressure, engine performance and emissions of the engine using the 4 kinds of the combustion chamber. Experimental results indicate that the effect of dc/H and nozzle protrusion are relatively small and there exists an optimum dc/H according to the combustion conditions. It is also found that the smoke emission is quite sensitive the overall combustion time where the 90 percentage of the combustion heat is released. The smoke mission increases by shortening the 90% combustion time while it decreases by delaying the 90% combustion time.

• Proceedings of the KSME Conference
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• 2001.06d
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• pp.790-795
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• 2001

Since the characteristics of combustion and pollutant in Diesel engines were mainly affected by the characteristics of in-cylinder gas flow and fuel spray, an understanding of those was essential to the design of the D.I. Diesel engines. The improvement of volumetric efficiency of air charging into combustion chamber is a primary requirement to obtain better mean effective pressure of an engine. Since the air resistances in intake and exhaust flow passages, valve lift and valve shape influence greatly to the volumetric efficiency, it is very important to investigate the flow characteristics of intake and exhaust port which develops air motion in the combustion chamber. This paper presents the results of an experimental investigation of steady flow through the various kinds of commercial cylinder head ports, and the development procedures of HHI's H21/32 prototype cylinder head ports.