• Journal of Environmental Science International
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• v.27 no.6
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• pp.437-445
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• 2018

Laser induced-exciplex-fluorescence (EXCIPLEX) proposed by Melton is used to visualize fuel vapor in spray combustion. However, in the EXCIPLEX method based on TMPD/naphthalene system, the TMPD : naphthalene ratio is strictly restricted to 1 : 9. In addition, fluorescence intensity due to the vapor phase is extremely weak. To overcome these drawbacks, we propose a new laser-induced-excimer fluorescence (EXCIMER) method to visualize the liquid and vapor phases simultaneously. The spatial distributions of liquid and vapor in fuel spray suspended by ultrasonic waves are compared using the EXCIPLEX and EXCIMER methods. The correlation between fuel vapor concentration and fluorescence intensity is experimentally investigated by measuring the fluorescence intensity of saturated vapor formed over liquid fuel at a controlled temperature. These experimental results indicate that the EXCIMER method is effective for evaluating fuel vapor visualization in spray combustion. Furthermore, the quantitative distribution of fuel vapor concentration can be correctly estimated by the EXCIMER method.

• 한국신재생에너지학회:학술대회논문집
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• 2008.05a
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• pp.503-506
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• 2008

Liquid hydrocarbon fuels, such as gasoline, kerosene, diesel and JP 8, can be good candidates for SOFC (solid oxide fuel cell) system fuel due to their high hydrogen density. Autothermal reforming (ATR) is suitable for liquid hydrocarbon fuel reforming because oxygen can decompose the aromatics in liquid fuel and steam can suppress the carbon deposition during catalytic reaction. The advantage of ATR is that it has a simple system construction due to exothermicity of ATR reaction. We control the exothermicity of reaction, make the reaction possible design a self-sustaining ATR reactor. A self-sustained 1kW-class kerosene autothermal reformer is introduced in this paper. The 1kW-class kerosene reformer was continuously operated for about 140 hours without degradation of reforming performance.

• Journal of the korean Society of Automotive Engineers
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• v.5 no.3
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• pp.33-44
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• 1983

This paper deals with the experimental study on the behavior of fuel (methanol) in intake manifold by using the basic apparatus which is manufactured the visible straight tube type model. In this study, the new device for liquid film thickness measurement and vaporization rate measurement are introduced to investigate the variation of liquid film thickness along the intake manifold and to observe the effect of vaporization of injected fuel. the results are summarized as follows: 1) The vaporization rate increases in proportion to decreasing of throttle valve angle and growing air fuel ratio. 2) The liquid film thickness along the intake manifold is mostly independent for the throttle valve angle in low air velocity and then affected in high air velocity, but the distribution of the liquid film thickness on circumferential position almost constant in the region of 300mm down stream from carburetor. 3) The mean liquid film thickness is 0.04 - 0.18mm in case of methanol in the region of air velocity Va = 12m/s - 55m/s and decreases with decreasing the throttle valve angle.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.717-720
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• 2011

Due to the depletion of fossil fuel, high oil price and global warming issue by green house gas such as CO2, clean synthetic fuel technologies using biomass, especially GTL(Gas To Liquid) technology, have been greatly attracted. This paper has examined and compared the worldwide technologies trend of natural gas reforming reaction, F-T(Fisher-Tropsch) synthesis and upgrading process which are three backbones of GTL technology.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.5
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• pp.51-66
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• 1997

A heat transfer model of the intake valve in a spark ignition engine is presented, which is calibrated with a number of the valve temperature profiles measured during engine warm-up for the gaseous fuel(propane). The valve is divided into four identical elements for which the assumption of lumped thermal mass is applied. The calibration is made so that the difference between the measued and simulated valve temperatures becomes minimal. Then the model is applied to the cases of the liquid fuel(indolene) to estimate the amount of the liquid fuel vaporized from the intake valve by assuming that fuel evaporation accounts for the deficit of the heat balance budget. The results of the model show quantitative contribution of each heat transfer source to the heat balance. The behavior of the calculated mass fraction of the fuel vaporized from the intake valve explains how the liquid fuel evaporate during engine warm-up. The mass fraction at warmed-up condition is closely related with the fraction directly targeted on the valve back by the fuel spray geometry.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.745-749
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• 2011

Two-dimemsional liquid-solid multiphase fluid dynamics was used to analyze the suspension and mix of liquid fuel and solid particles in fuel tank installed mixing impeller. In this paper, the multiphase flow was modeled using Eulerian Grandular Multiphase model. Experimental measurements of the axial distribution of solids concentration in stirred tanks under 12vol% solid loading were used for comparison with the CFD simulation. Four cases for the impeller location and flow pumping direction also were reviewed under 10.5% solids loading and 700rpm in fuel mix tank. The result of quality of suspension was compared with each cases and the impeller location and operation of mixing fuel tank was established.

• New & Renewable Energy
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• v.3 no.4
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• pp.8-15
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• 2007

Liquid water in flow channel is an important factor that limits the steady and transient performance of PEM fuel cells. A computational fluid dynamics study based on the volume-of-fluid [VOF] multi-phase model was conducted to understand the two-phase flow behavior of liquid water in cathode gas channels. The liquid water transport in $180^{\circ}{\Delta}$ bends was investigated, where the effects of surface characteristics (hydrophilic and hydrophobic surfaces], channel geometries (rectangular and chamfered corners], and air velocity in channel were discussed. The two-phase flow behavior of liquid water with hydrophilic channel surface and that with hydrophobic surface was found very different; liquid water preferentially flows along the corners of flow channel in hydrophilic channels while it flows in rather spherical shape in hydrophobic channels. The results showed that liquid water transport was generally enhanced when hydrophobic channel with rounded corners was used. However, the surface characteristics and channel geometries became less important when air velocity was increased over 10m/s. This study is believed to provide a useful guideline for design optimization of flow patterns or channel configurations of PEM fuel cells.

• Journal of the Korean Society of Safety
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• v.31 no.2
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• pp.33-40
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• 2016

Liquid fuel can be easily exploded and release more energy of detonation than conventional explosives because it has different explosion mechanism. In order to analyze dispersion characteristics of liquid fuel for the safety purpose, two tests are conducted. First, pre-test, which is a computer simulation, is carried out by a software called ANSYS AUTODYN to eliminate the effect of a canister that usually causes irregular dispersion of the fuel. Second, field test is performed to find out the amount and density effect of bursting charge. High speed cameras are installed in front of the canister to visualize the mechanism. Velocity, area and radius of the dispersed cloud are measured by image processing software, these are shown that the amount of bursting charge affects cloud velocity and area but density is not a significant factor of cloud formation.

• Journal of ILASS-Korea
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• v.15 no.1
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• pp.38-43
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• 2010

The LPG(Liquefied Petroleum Gas) fuel attracts attention as a clean alternative fuel. In order to further reduce the exhaust emission and improve performance in LPG engines, the LPLi(Liquid Phase LPG Injection) system is used. In LPLi system, the fuel pump performance is important for keeping the LPG over it's saturated vapor pressure. An external fuel pump is needed to improve the durability for LPG engines. This paper predicted the variation of fuel properties on the LPLi system with an external fuel pump. From each component's thermodynamic model, an 1-D simulation is developed for LPLi system with an external fuel pump. Then the 1-D simulation data analyzed and compared with the rig-test. The 1-D simulation and the rig-test produced similar results.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.251-253
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• 2017

Numerical study of air-blast type injector for low emission aircraft engines was conducted. Volume-of-fluids approach was used to track interface of fuel and air. Primary atomization of fuel stream was visualized, and thickness and mean velocity at the injector exit was calculated. Liquid fuel injected from fuel slots joined together as a thin film on preflimer surface, and interacted with swirling air. As instability on the fuel surface increased, separation of fuel as ligaments and droplets occured. The film thickness and velocity were used to as fuel injection boundary condition for reactive flow simulation. Primary reaction zone was formed in vicinity of the fuel nozzle, creating a stable flame inside the combustor.