• Journal of ILASS-Korea
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• v.14 no.2
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• pp.49-58
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• 2009

Non-edible vegetable oils instead of edible vegetable oils as a substitute for diesel fuel are getting a renewed attention because of global reduction of green house gases and concerns for long-term food and energy security. Out of various non-edible vegetable oils, karanja, mahua, linseed, rubber seed and cotton seed oils are selected in this study. A brief review of recent works related to the application of the above five vegetable oils and its derivatives in CI engines is presented. The production technologies of biodiesel based on non-edible vegetable oils are introduced. Problems in vegetable oil or biodiesel fuelled CI engine are included. In addition, future works related to spray characteristics of non-edible vegetable oil or biodiesel from it are discussed. The biodiesel fuel, irrespective of the feedstock used, results in a decrease in the emission of hydrocardon (HC), carbon monoxide (CO), particulate matter (PM) and sulphur dioxide ($SO_2$). It is also said to be carbon neutral as it contributes no net carbon dioxide to the atmosphere. Only oxides of nitrogen (NOx) are reported to increase which is due to oxygen content in the biodiesel fuel. The systematic assessment of spray char-acteristics of neat vegetable oils and its blends, neat biodiesel and its blends f3r use as diesel engine fuels is required.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.1
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• pp.1-8
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• 2005

The spray prepared for direct fuel injection into cylinder is of great importance in a DISI(Direct Injection Spark Ignition) engine. The interaction between air flow and fuel spray was investigated in a steady flow system embodied in a wind tunnel to simulate the variety of in-cylinder flow conditions in the DISI engine. The Mie-scattering images presented the macroscopic view of the liquid spray fields interacting with cross-flow Particle sizes of fuel droplets were measured with phase Doppler anemometer(PDA) system. A faster cross-flow field made SMD larger and $D_10$ smaller. The atomization and evaporation processes with a DISI injector were observed and consequently utilized to construct the database on the spray and fuel-air mixing mechanism as a function of the flow characteristics.

• Journal of ILASS-Korea
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• v.22 no.4
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• pp.218-224
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• 2017

In order to improve the quality of air in urban areas, the emission regulations are being strengthened by the government. The on-road test of light-duty vehicles was started with PEMS because certification test mode does not sufficiently reflect on-road conditions. Therefore, The PEMS-based test was implemented from Sep. 2017 in Europe and Korea. However, this is lack of data on various on-road patterns in Korea. The purpose of the present study has analyzed the effect of speed per acceleration and acceleration on NOx emission on-road driving. The test route consisted of urban, rural, and motorway in Seoul. This study has been conducted by Euro-6 vehicles using on SCR system with PEMS. The on-road emission characteristics were evaluated by moving averaging windows (MAW) method. In results, RDE-NOx by severe driving pattern has been 1.4 times higher than soft driving pattern NIER Route 1.

• Journal of ILASS-Korea
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• v.10 no.3
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• pp.38-44
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• 2005

The direct injection into the cylinders has been regarded as a way of the reduction in fuel consumption and pollutant emissions. The spray produced from the injector of DIS(Direct Injection Spark Ignition) engine is of paramount importance in DISI engines. Fan-spray injector as well as swirl-spray injector was developed and utilized to the DISI engines. The interaction between air flow and fuel spray was investigated in a steady flow system embodied in a wind tunnel to simulate the variety of flow inside the cylinder of the DISI engineer. The direct Mie scattered images presented the macroscopic view of the liquid spray fields interacted with crossflow. Particle sizes of fuel droplets were measured with phase Doppler anemometer(PDA) system. A faster cross-flow field made SMD larger and $D_{10}$ smaller. The experiments show the interaction of air flow field and the fuel spray field of fan-spray. The results can be utilized to construct the data-base for the spray and fuel-air mixing mechanism as a function of the flow characteristics.

• Journal of ILASS-Korea
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• v.8 no.2
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• pp.38-45
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• 2003

This study was carried on the combustion characteristics of a pure light oil and emulsified fuels at high-pressure injection in a spray combustion installation, The volume fractions of water in an emulsion were varied up to 30% and the injection pressures were 7.5, 100, 200, and $300kg_f/cm^2$. The concentrations of NOx and the average temperatures of flame were measured. And Images of OH radical using ICCD camera and instantaneous schlieren photography of flames were photographed. It was found that the temperature distribution of axial distance in the emulsified fuels was increased in the upstream and decreased in the down stream. The temperature distribution of radial distance was high at the peripheral regions of the spray in the upstream and at the central regions of spray in the downstream, The intensity of OH radical was denser at the water content 10% than at the pure light oil over the injection pressure $200kg_f/cm^2$.

• Journal of ILASS-Korea
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• v.20 no.4
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• pp.207-216
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• 2015

Recently, the researches for air pollutant control technologies have been performing in Korea, while considering an one of the latest main topics as problems on air pollutant control. However, it is difficult to investigate emission amount of air pollutant by passenger cars, because of lack of the domestic information about mobile source; the number of research institutes are less in the whole. Especially, the informations on registered numbers and emissions of motorcycles are less. Thus, in this study, the analysis that is based on experimental results was conducted for finding out source profiling and emission characteristics on motorcycles exhaust. For these experiments, the domestic motorcycles were chosen and evaluated by EURO III standard. From the result, controlled pollutants (CO, HC, NOx) were met to EURO III, but low displacement motorcycles showed a higher incomplete combustion reaction than that of 250 cc motorcycles. Additionally, uncontrolled pollutants (BTEX and 1,3-butadiene) were decreased with increasing a displacement of motorcycles. However, the emission trend of aldehydes was not followed that of those; the formaldehyde ratio increased upto approximately 33%, with increasing a displacement of motorcycles. In the future, it would be used to support the CAPSS as basic data of Korea.

• Journal of ILASS-Korea
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• v.20 no.4
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• pp.261-267
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• 2015

The main purpose of this study is to provide the information of soot generation of toluene fuel droplet. To achieve this, this paper provides the experimental results on the different initial diameter of toluene droplet combustion characteristics conducted under equivalent ambient pressure ($P_{amb}$) and oxygen concentration ($O_2$) conditions. Visualization of single fuel droplet was performed with high resolution CCD camera and visualization system. At the same time, ambient pressure ($P_{amb}$) and oxygen concentration ($O_2$) were maintained by ambient condition control system. Soot volume fraction ($f_v$) was analyzed and compared on the basis of intensity ratio ($I/I_0$) of background image. The result of soot generation was almost the same regardless of initial droplet diameter since thermophoretic flux is not much changed under the same ambient conditions. Soot standoff ratio (SSR) of 2 mm diameter showed unstable variation characteristics due to the short available measuring time.

• Journal of ILASS-Korea
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• v.20 no.4
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• pp.223-229
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• 2015

This paper was designed to investigate emission characteristics of regulated pollutants (CO, HC, NOx and PM) from 134 diesel and gasoline passenger cars based on emission standards according to fuel additives. The experiments using chassis dynamometer were conducted under NEDC and CVS-75 modes. Comparison for fuel additive management and test between Korea, USA, EU and Japan, Korea was more strict than others. The fuel additives of this study was satisfied within fuel manufacturing standards. For with/without fuel additives according to diesel emission standards, NOx of EURO 4 and EURO 5 showed a relatively similar tendency. In the case of PM reduction rate, EURO 5 was over 20% increased than EURO 4. In the case of standard deviation/average ratio for gasoline vehicles, variation interval was big for LEV 23.3~58% and ULEV 31.6~56.4%. Following the imposition of stricter regulations (EURO 5 and ULEV), difference rate for standard deviation was big. Especially, in the case of diesel vehicles, difference rate for NOx 68% and PM 48% was most big. The results of present study will be of assistance in completing the legislative process and will provide basic data to set up emission standards for fuel additives in Korea.

• Journal of ILASS-Korea
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• v.20 no.4
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• pp.217-222
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• 2015

In this study, Injection rate tests of a Diesel common-rail injector have been performed with injection volume measurement type injection rate test system EMI21 for construction of injector model can be used in an engine calibration mean valued model. The measuring principle of the test system is based on measurement of dispalcement of a movable measurement piston by the volume of fluid released by the injector. From these injection rate test results, the characteristics on shape of instantaneous injection rate and injection fuel amount have been investigated and injection fuel amount calculation equation based on test results has been newly constructed. This equation is very simple and calculation error is less than 5% with test results for wide range injection pressure (200~1800 bar) and injection duration ($200{\sim}1800{\mu}s$) conditions. So, it is anticipated that newly constructed simple injection fuel amount model in this study can be efficiently used on engine calibration and control model.

• Journal of ILASS-Korea
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• v.12 no.4
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• pp.204-210
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• 2007

The worldwide energy problem and global warming cause the need of alternative fuels which feature low carbon-dioxide emission and another energy source. Liquefied Petroleum Gas (LPG) is one of the alternative fuels widely used as domestic and transportational fuel. The third generation LPLi fuel supply system has merits in the increase of engine power and low emissions. The injectors used in LPLi system should overcome a leakage problem and satisfy the durability conditions. Therefore, 1000 hour durability test of the injectors was carried out throughout this research. First, the spray pattern and the penetration length of the selected injectors is graphically shown. Next, the leakage amount with respect to the injection cycle is introduced. Finally, the shapes of nozzle holder and nozzle tip after durability test was investigated by analyzing the microscopic image of the injector tip. The variation in the shape of nozzle tip mainly due to the residue of rubber materials is found to be the reason for leakage.