• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.2
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• pp.8-15
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• 2003

During cold operation, fuel injection in the intake port directly contributes to the unburned hydrocarbon formation in spark ignition engines. The relationship between injection parameters and HC emission behavior was investigated through a series of experiments. Spray behavior of port fuel injectors was characterized through a quantitative evaluation of mass concentration of liquid fuel by a patternator and PDA(Phase-Doppler. Anemometer). A 6-hole injector was found to produce finer spray than single hole injector. Using a purpose-built wall, the wetted fuel was measured, which was mostly affected by wall temperature. HC emissions were measured in a production engine varying coolant temperature$(20~80^{\circ}C)$, also with respect to the different types of injectors. In the 6-hole injector application, the engine produced less HC emission in low coolant temperature region. Though it produces much more amount of wetting fuel, it has the advantages of finer atomization quality. In high coolant temperature region, there was little effect by different types of injectors. The control schemes to reduce HC emissions during cold start could be suggested from the findings that the amount of fuel supply and HC emission could be reduced by utilizing fine spray and high intake wall temperature.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.423-431
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• 2010

In order to investigate the effect of fuel injection hole configuration within the scramjet combustor, experiment and quasi-one-dimensional analysis was performed. And the results were compared with experiment and analysis result which were performed in 2008 with same facility and test condition. Fuel injection hole size was decreased and quantity was increased. However the depth of fuel penetration and fuel flow were maintained. As a test result, combustion performance was increased significantly with no-cavity injector and slightly with plain-cavity. However, combustion performance with zigzag-cavity was decreased.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.5
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• pp.78-85
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• 2000

This study is to develop the diesel engine which has 6 cylinder natural aspiration direct injection type of 7.4$\ell$ with high performance, low emissions and low fuel consumption Finally the developed engine meets Korean `98 exhaust emission regulation for the city bus of heavy duty diesel engine by optimizing the various combustion parameters affecting performance and exhaust emissions. Combustion parameters are the swirl ratio of intake ports, the profile of injection pump`s cam affecting injection pressure, the design features of piston bowl of injection pump`s cam affecting injection pressure, the design features of piston bowl of combustion chamber and injector`s hole size. Through experimental analysis, various combustion parameters are optimized and the results are as follows; the swirl ratio is 2.20, the profile of injection pump`s cam is concave and re-entrant ratio, inner diameter of piston bowl and hole diameter of injector is 0.88,$\psi$64.0mm and $\psi$0.25mm respectively.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.142-147
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• 2004

The flow in the LOX manifold of liquid rocket has been investigated using a CAE technique with an objective of economical modeling of injection holes in order to reduce the overall computational cost of flow analysis during the optimal rocket design procedure. The computational geometry is very close to that of the actual rocket design and the flow condition through the injection holes resembles that in the actual manifold of the liquid rocket. The result shows that the flow in the plane just above the injection holes is not uniformly distributed in terms of pressure and mass flow rate and this is attributed to the large-scale flow patterns present the LOX manifold. Thus, the flow physics should be understood correctly before making any attempt to model the injection holes. In the present study, several boundary conditions which were designed to effectively replace the presence of injection holes have been tested and it was found that a simple modeling can be possible by mimicking the actual geometry of the injection holes. By using this simple injection hole modeling, it was able to obtain about 30% reduction in computational cost but it was still able to reproduce the flow patterns correctly. Also the flow has been analyzed after incorporating a couple of different types of pre-distributors in LOX manifold and the effect of those will be discussed.

• Structural Engineering and Mechanics
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• v.59 no.1
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• pp.37-57
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• 2016

Reservoir geomechanics can play an important role in hydrocarbon recovery mechanism. In $CO_2$-EOR process, reservoir geomechanics analysis is concerned with the simultaneous study of fluid flow and the mechanical response of the reservoir under $CO_2$ injection. Accurate prediction of geomechanical effects during $CO_2$ injection will assist in modeling the Carbon dioxide recovery process and making a better design of process and production equipment. This paper deals with the implementation of a program (FORTRAN 90 interface code), which was developed to couple conventional reservoir (ECLIPSE) and geomechanical (ABAQUS) simulators, using a partial coupling algorithm. A geomechanics reservoir partially coupled approach is presented that allows to iteratively take the impact of geomechanics into account in the fluid flow calculations and therefore performs a better prediction of the process. The proposed approach is illustrated on a realistic field case. The reservoir geomechanics coupled models show that in the case of lower maximum bottom hole injection pressure, the cumulative oil production is more than other scenarios. Moreover at the high injection pressures, the production rates will not change with the injection bottom hole pressure variations. Also the FEM analysis of the reservoir showed that at $CO_2$ injection pressure of 11000 Psi the plastic strain has been occurred in the some parts of the reservoir and the related stress path show a critical behavior.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2012.05a
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• pp.169-169
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• 2012

Molybdeum oxide-doped 4,4',4"-tris(2-naphthyl(phenyl)amino)tri- phenylamine (2-TNATA) layer 의 도핑농도가 75%일 때 OLED 소자의 성능이 향상되었다. Hole transport layer (HTL) 로 사용된 MOOX-doped 2-TNATA layer는 hole-injection barrier height를 낮추어서 효율적인 홀주입특성을 보였다. 그러나 도핑농도가 75%이하일 때는 소자 특성이 나빠짐을 알 수 있었다.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.6
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• pp.745-752
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• 2003

Injection technology is one of the important technologies in a diesel engine. Many studies have done on the injection system. In this study, the fuel chamber geometry, the orifice ratio and the needle lift of the injection valve of a diesel engine for generating electricity are varied and tested. The injection pressure, duration and spray shapes are produced with pressure transducer, needle lift sensor and highspeed camera. The result shows that the nozzle hole size has influence on the rail pressure and injection duration sensuously.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.1061-1064
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• 2009

Through dark injection space-charge-limited current (DI-SCLC) and trap-free SCLC measurements, it has been demonstrated that an indium tin oxide (ITO)/buckminsterfullerene ($C_{60}$) electrode can form a quasi-Ohmic contact with N, N'-bis (naphthalen-1-yl)-N, N'-bis(phenyl) benzidine (NPB). The DI-SCLC results show a clear peak current along with a shift of the peak position as the field intensity varies, implying an Ohmic (or quasi-Ohmic) contact. A theoretical simulation of the SCLC also shows that ITO/$C_{60}$ forms an Ohmic contact with NPB. The Ohmic contact makes it possible to estimate the NPB hole mobility through the use of both DI-SCLC and trap-free SCLC analysis. This also contributes to a reduction in power consumption.

• Journal of Advanced Marine Engineering and Technology
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• v.30 no.6
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• pp.662-668
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• 2006

The effects of fuel injection nozzle hole on the NOx emission and fuel oil consumption of medium speed diesel engine HYUNDAI HiMSEN 6H21/32 engine are investigated by engine performance simulation. The results of performance simulation are verified by experimental results of NOx omission fuel oil consumption, cylinder pressure, and heat release rate according to the variation of the number of fuel injection nozzle hole and engine load. The performance simulations are also carried out to optimize the fuel injection nozzle of 6H21/32 engine in respect to the NOx emission and fuel oil consumption. The engine performance measurements are performed to verify the results of performance simulation and to investigate the effects of fuel injection nozzle on engine performance. The results of measurement indicate that significant NOx reduction can be achieved with minimum deterioration in fuel oil consumption by optimizing the geometry of fuel injection nozzle on 6H21/32 engine.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.69-70
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• 2006

We studied increasement of efficiency of Organic Light-emitting Diodes depending on thickness variation of LiF, Material of Electron Injection Layer in structure of ITO/Hole Injection Layer (PTFE)/Hole Transportion Later (TPD)/Emitting Layer (Alq3)/Electron Injection Layer (LiF)/Al. TPD and $Alq_3$ is deposited as rate of 1.3~1.5 [${\AA}/s$] in high vacuum ($5{\times}10^{-6}$ [torr]). In result of these studies, we can know maximum efficiency in 0.7 [nm], thickness of LiF. And samples with electron injection material are increased about 5-fold in maximum efficiency in compare with sample without electron injection material.