• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.1
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• pp.14-22
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• 2010

Hybrid Electronic Vehicle (HEV) is one of the solutions of high oil price and environment problem. Recently, study of HEV is important for automobile industry. However HEV has a lot of components and there are many cases for assembling, it's impossible to test results from assembling by using real vehicles. To solve this problem, hybrid system simulator is required. The purpose of this study is to develop and optimize of engine module for hybrid system simulator. The commercial 1-D engine simulation program, WAVE is used to get the engine capacity and performance data and 1-D simulation model of base engine is compared with engine experiment results. Using the data, the engine module is developed based on the MATLAB Simulink. There are blocks of base engine, Single-CVVT engine and Dual-CVVT engine. The effect of acceleration and deceleration is applied to each engine block. In addition, the control and processing logics for CIS technology are developed. Finally the simulator operates FTP-72 mode test.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.9
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• pp.727-734
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• 2015

Recently, because of the increased oil prices globally, there have been studies investigating the improvement of fuel-conversion efficiency in internal combustion engines. The improvements realized in thermal efficiency using lean combustion are essential because they enable us to realize higher thermal efficiency in gasoline engines because lean combustion leads to an increase in the heat-capacity ratio and a reduction of the combustion temperature. Gasoline direct injection (GDI) engines enable lean combustion by injecting fuel directly into the cylinder and controlling the combustion parameters precisely. However, the extension of the flammability limit and the stabilization of lean combustion are required for the commercialization of GDI engines. The reduction characteristics of three-way catalysts (TWC) for lean combustion engines are somewhat limited owing to the high excess air ratio and low exhaust gas temperature. Therefore, in the present study, we assess the reaction of exhaust gases and their production in terms of the development of efficient TWCs for lean-burn GDI engines at 2000 rpm / BMEP 2 bar operating conditions, which are frequently used when evaluating the fuel consumption in passenger vehicles. At the lean-combustion operating point, $NO_2$ was produced during combustion and the ratio of $NO_2$ increased, while that of $N_2O$ decreased as the excess air ratio increased.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.1
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• pp.9-16
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• 2003

According as the industry was developed, the pollution of the environment and atmosphere rose up to the surface. So, the focus is now concentrated on the engines of affinity for nature. And the investigators make more effort to the improvement in the performance of engines, depending to the prices of oil and the anxiety about the exhaustion of the fossil fuel go up. So the GDI engines head up for these necessities. In this experimental study, the spray flow characteristics for a commercial injector equipped in the present GDI engine were investigated, which had a strong influence on the engine performance and emissions. The experiment was performed at the injection pressures of 1, 3, 5 and 7MPa under the atmospheric condition. A PDPA system was used to specify the flow characteristics of the spray. Also, the global spray behavior classified into three regions as leading, main spray and vortex cloud region, was analyzed by using a visualization system. And the regions were compared with each other.

• Analytical Science and Technology
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• v.16 no.5
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• pp.339-348
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• 2003

Determination of some PAHs in used engine oils have been carried out by extraction of the components into acetonitrile followed by GC/FID and synchronous spectrofluorimetric technique. 7 PAHs, such as acenaphthene (Ace), anthracene (Anth), benzo(a)pyrene (BaP), chrysene (Chry), phenanthrene (Phen), fluoranthene (Ft), and perlyrene (Per) in used engine oil sample were able to determine separately by synchronous spectrofluorimetry. Calibration curves for those components were linear for the concentration range of 0.4~166 ppb PAHs with the corelation factor of 0.9985~0.9999. The peak areas produced by GC/FID split ratio program were used for the calibration curves of the other 8 PAHs. Detection sensitivity of the synchronous spectrofluorimetry seems to be 100 times more sensitive than GC/FID method. The total amount of PAHs in the used engine oil were 5.5 ng/g for LNG (bus), 10.5 ng/g for LPG(taxi), 92.2 ng/g for gasoline-passenger car, and 130 ng/g for diesel trailer, respectively.

• Journal of ILASS-Korea
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• v.18 no.2
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• pp.106-111
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• 2013

Adulterations fuel have been using in the vehicle in these days. Because gasoline, diesel prices are rising every day. so people find more cheap price fuel. Adulterations fuel caused a serious air pollution problems. Adulteration fuel were made from waste engine oil, waste paint. According to Government regulations permit to be used recycle fuel(adulteration fuel) only in industrial boiler. Unburned fuel pollutants are effected to human health. In this paper, the hazardous air pollutants characteristics in the diesel vehicles according to adulterations of vehicle fuels were carried out in the NEDC test mode in chassis dynamometer. It is revealed that the all of the regulation pollutants (THC, NOx, CO and PM) emission in the adulterations of vehicle fuels was increased also the green house gas, $CO_2$ was increased. In the hazardous air pollutants characteristics, the VOCs(Volitile Organic Compounds) BTEX(Benzene, Toluene, Ethylbenzene, Xylene) emissions in the adulterations of vehicle fuels showed higher level than these in the diesel fuels.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.9-15
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• 2018

The turbochargers, which are used widely in diesel and gasoline engines, are an effective device to reduce fuel consumption and emissions. On the other hand, turbo-lag is one of the main problems of a turbocharger. Bearing friction losses is a major cause of turbo lag and is particularly intense in the lower speed range of the engine. Current turbochargers are mostly equipped with floating bearings: two journal bearings and one thrust bearing. This study focused on the bearing friction at the lower speed range and the experimental equipment was established with a drive-motor, load-cell, magnetic coupling, and oil control system. Finally, the friction losses of turbochargers were measured considering the influence of the rotating speed from 30,000rpm to 90,000rpm, oil temperature from $50^{\circ}C$ to $100^{\circ}C$, and oil supply pressure of 3bar and 4bar. The friction power losses were increased exponentially to 1.6 when the turbocharger speed was increased. Friction torques decreased with increasing oil temperature and increased with increasing oil pressure. Therefore, the oil temperature and pressure must be maintained at appropriate levels.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.585-591
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• 2017

Turbocharging is widely used in diesel and gasoline engines as an effective way to reduce fuel consumption. But turbochargers have turbo-lag due to mechanical friction losses. Bearing friction losses are a major cause of mechanical friction losses and are particularly intensified in the lower speed range of the engine. Current turbochargers mostly use oil bearings (two journal bearings and one thrust bearing). In this study, we focus on the bearing friction in the lower speed range. Experimental equipment was made using a drive motor, load cell, magnetic coupling, and oil control system. We measured the friction losses of the turbocharger while considering the influence of the rotation speed, oil temperature, and pressure. The friction power losses increased exponentially when the turbocharger speed increased.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.11
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• pp.1005-1013
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• 2010

This study was conducted to assess the spray control of flash boiling with mixed fuel in consideration of HCCI (Homogeneous Charge Compression Ignition) engine condition. Mixed fuel existing in two phase regions can control the process of mixture formation under low temperature and density by using the spray resulting from flash boiling which is able to induce rapid evaporation of fuel spray as well as the evaporation of high boiling point component. Because HCCI engine injects the fuel early under ambient conditions, it can facilitate the chemical control of ignition combustion and physical control such as breakup and atomization of liquid fuel by flash boiling of mixed fuel which consists of highly ignitable light oil and highly volatile gasoline. This study was conducted by performing video processing after selected composition and molar fraction of the mixed fuel as major parameters and photographed Schlieren image and Mie scattered light corresponding to the flash boiling phenomenon of the fuel spray that was injected inside a constant volume vessel. It was found that flash boiling causes significant changes in the spray structure under relatively low temperature and density. Thus, we analyzed that the flash boiling spray can be used for HCCI combustion by controlling the mixture formation at the early fuel injection timing.