• 한국분무공학회지
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• 제22권4호
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• pp.197-202
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• 2017

The objective of this study is to investigate the effects of low-temperature combustion (LTC) on the correlations of combustion characteristics and reduction of exhaust emissions in a small DI diesel engine with biodiesel fuel. In order to analyze the combustion, exhaust emission characteristics and distribution of nano size particles for biodiesel were investigated. In addition, to evaluate the effect of LTC on the combustion and emission characteristics, 30 and 50% of cooled-EGR rates were investigated. From these results, it revealed that the influence of LTC on the combustion characteristics showed that the ignition delay significantly increased and reduces peak heat release rate of premixed combustion by lowering reaction rate. With 50% EGR and advanced injection timing, soot and $NO_x$ emissions were simultaneously reduced.

• 한국분무공학회지
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• 제22권4호
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• pp.190-196
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• 2017

The aim of this work is to investigate the combustion and exhaust emission characteristics of low-temperature combustion (LTC) at various EGR test conditions using a single cylinder common-rail diesel engine. In high EGR rate combustion mode with DME fuel, 30% (${\Phi}=0.61$) and 50% (${\Phi}=0.86$) of EGR were respectively examined, and then the combustion, exhaust emissions, nano-particle characteristics of each cases were measured. From these results, it revealed that The ignition delay and combustion duration are prolonged as the increase of EGR rate. In addition, at an advanced injection timing (BTDC $30^{\circ}$), ignition delays were fairly increased because the dilution effect of EGR and also low charge in-cylinder temperature created a lean mixture, thus decreased the peak release rate.

• 한국분무공학회지
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• 제7권2호
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• pp.16-21
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• 2002

Liquefied petroleum gas (LPG) has been used as motor fuel due to its low emissions and low cost. This study addresses the analysis of the LPG spray behavior near injection nozzle. The LPG spray photographs are compared with sprays of diesel fuel at the same conditions. The LPG spray photos show that the dispersion characteristic depends very sensuously on the ambient pressure soon after injection. The spray angle is very wide in a low ambient pressure condition until the saturated pressure at this test condition, but the angle value is quickly reduced at the condition over the pressure.

• 한국분무공학회지
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• 제4권3호
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• pp.24-31
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• 1999

The engine performance and combustion characteristics of methanol blended fuel of spark ignition engine were discussed on the basics of experimental investigation. The effects of methanol blending fuel on combustion in cylinder were investigated under various conditions of engine cycle and blending fuel on combustion in cylinder were investigated tinder various conditions of engine cycle and blending ratios. The results showed thai the engine performance was influenced by the methanol blending ratio and the variations of operating conditions test engine. The increase of fuel temperature brought on the improvement of combustion characteristics such as cylinder pressure. the rate of pressure rise and heat release in an engine. The burning rate of fuel-air mixture, the exhaust emissions and the other characteristics of performance were discussed also.

• 한국분무공학회지
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• 제20권4호
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• pp.241-246
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• 2015

The objective of the current study is to develop an 1D thermoacoustic model for predicting basic characteristics of combustion instability and to investigate effects of key parameters on the instabilities such as effects of flame geometry and acoustic boundary conditions. Another focus of the paper is placed on limit cycle prediction. In order to improve the model accuracy, the 1D model was modified considering the actual flame location and flame length (i.e. distribution of time delay). As a result, it is found that the reflection coefficients have a great effect on the growth rate of the instabilities. In addition, instability characteristics are shown to be strongly dependent upon the fuel compositions.

• 한국분무공학회지
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• 제20권4호
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• pp.230-235
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• 2015

The demands for reliable particle cloud temperature measurement exist in many process industries and scientific researches. Particle cloud temperature measurements depend on radiation thermometry at two or more color bands. In this study, we developed a sensitive, fast response and compact online infrared two-color probe to measure the temperature of a particle cloud in a phase of two field flow (solid-gas). The probe employs a detector contained two InGaAs photodiodes with different spectral responses in the same optical path, which allowed a compact probe design. The probe was designed to suit temperature measurements in harsh environments with the advantage of durability. The developed two-color probe is capable of detecting particle cloud temperature as low as $300^{\circ}C$, under dynamic conditions.

• 한국분무공학회지
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• 제2권2호
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• pp.43-50
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• 1997

The purpose of this investigation is to carry out, the influence factor on the fuel spray characteristics for improve the engine combustion performance and exhaust omission in direct injection type diesel engine. The fuel properties, fuel spray structure and the shape or the piston surface of diesel engine play an important role of engine combustion process and exhaust emission. In order to obtain the effect of using auxiliary chamber and emulsified fuel on the fuel spray characteristics the experiment un conduct with single cylinder direct injection type diesel engine to examine the engine performance and gas emission. The results of this investigation showed that the increase auxiliary chamber volume and emulsified fuel give an effect on the fuel spray characteristics by reduced the concentration of nitric oxide emission in the combustion chamber. Also it can improve the combustion characteristics such as cylinder pressure, rate of pressure rise and rate of heat release.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.454-456
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• 2009

N-Type $SbI_3$ doped $95%Bi_2Te_3+5%\;Bi_2Se_3$ compounds were newly fabricated by the combination of gas atomization process and Magnetic Pulsed Compaction process. The thermoelectric properties of the MPCed bulks according to consolidation temperatures were investigated by a combination of microscopy, XRD and thermoelectric property testing. The microstructure of MPCed bulk shows homogeneous and fine distribution through consolidated bulks due to the high solidification of compound powders. The research presented the challenges toward the successful consolidation of thermoelectric powder using magnetic pulsed compaction (MPC) and analysis of thermoelectric properties of the consolidated bulks.

• 한국분무공학회지
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• 제2권3호
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• pp.32-43
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• 1997

A comparison of predicted molar volume, vapor - liquid equilibrium, enthalpy of vaporization, droplet size history. and vaporization rates with several forms of equation of state has been made. The equation of state (EOS) investigated in this study includes the EOS given by Redlich - Kwong, the Soave - Redlich - Kwong, and the Peng - Robinson. Numerical results indicate that the Peng - Robinson EOS yields more accurate predictions of vapor - liquid equilibrium under a broader range of temperature and pressure conditions, especially at high pressures and near the critical point.

• 한국분무공학회지
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• 제2권3호
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• pp.44-50
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• 1997

Bio-diesel oil is a great possibility to solve the pollution problem caused by the exhaust gas from diesel engine vehicles. Recently the use of bio-oils in disel engines has received considerable attention to the forseeable depletion of world oil supplies. So, Bio-diesel oil has been attracted with attentions as an alternative and clean energy source. The objective of this paper is to experimentally investigate the characteristic of performance using light oil, rice-bran oil, heated rice-bran oil, rice-bran oil treated with ultrasonic energy. We included rice-bran oil and applied ultrasonic energy to highly viscous bio-oils. These methods seems to have never been tried yet. The final data may be able to be applicated for the design of the diesel engine using an alternative fuel.