• 한국가시화정보학회지
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• 제3권2호
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• pp.3-13
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• 2005

The optical patterantor provides the high resolution and quantitative information of the spray. Fuel distribution and Sauter Mean Diameter (SMD) can be measured from fluorescence and Mie-scat-tering images. To correct the attenuation of the laser beam and signal in dense spray region, the method to find the geometric mean of the signal intensities obtained from two cameras was evaluated and verified in a solid-cone spray. In high pressure environment, the increased number density of the droplets cause multiple scattering. The optical patternation technique using a laser beam instead of a laser sheet was applied to minimize the multiple scattering problem. The pattern of a coaxial spray was changed from hollow-cone to solid-cone shape, and the spray angle was reduced as the ambient pressure increased from 0.1 to 4.0 MPa.

• Journal of Mechanical Science and Technology
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• 제17권11호
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• pp.1812-1819
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• 2003

This paper presents the effect of injection pressure on the atomization characteristics of high-pressure injector in a direct injection gasoline engine both experimentally and numerically. The atomization characteristics such as mean droplet size, mean velocity, and velocity distribution were measured by phase Doppler particle analyzer. The spray development, spray penetration, and global spray structure were visualized using a laser sheet method. In order to investigate the atomization process in more detail, the calculations with the LISA-DDB hybrid model were performed. The results provide the effect of injection pressure on the macroscopic and microscopic behaviors such as spray development, spray penetration, mean droplet size, and mean velocity distribution. It is revealed that the accuracy of prediction is promoted by using the LISA-DDB hybrid breakup model, comparing to the original LISA model or TAB model alone. And the characteristics of the primary and secondary breakups have been investigated by numerical approach.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2002년도 제24회 KOSCO SYMPOSIUM 논문집
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• pp.11-15
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• 2002

Experimental studies on effects of the interaction of duplex swirl injector and the liquid temperature on the spray characteristics were conducted. Water and fuel were used as a test fluid for the experiments. The drop size distributions of the liquid spray were measured with Malvern particle sizer. The liquid temperature and distance of injectors were adopted as the operating parameter. The results show that SMD decrease as the increases of fuel temperature and pressure. The spray angle increase as fluid temperature increases. For fuel spray, SMD of impacting surface increase as the distance of injectors is lengthened.

• 한국연소학회지
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• 제16권1호
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• pp.58-65
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• 2011

Thermal spray technology has been used in many industrial application. Especially, thermal spray coating have been employed with the purposes of achieving better resistances in abrasion, heat and corrosion. In the previous studies on the thermal spray coating, thermal spray characteristics from the perspective of combustion engineering have not been investigated sufficiently, while the material characteristics of the coated substrates have been investigated widely. In this study, the effect of spray particles on the flame behavior was experimentally investigated. The amount of the injected particles was measured using the light scattering method and the temperature of the particles was estimated using a two-color method. Various flame-spray interactions were observed and it was found that the high temperature zone near the flame is elongated by particles density. Based on these results, the applicability of the light scattering method and the two-color method was discussed.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.96-97
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• 2014

The purpose of this study is to analyze the adhesion strength of metal spray coating system in steel using high-frequency arc metal spray method. For the purpose the experimental factor such as surface roughness was selected at 3 levels. As a result of experiment, it appeared that high-frequency arc metal spray method had higher adhesion strength than existing metal spray method. Especially, Al-Mg showed the highest adhesion strength than other metals. In case of surface roughness, the higher roughness steel has, the higher adhesion strength appeared.

• 한국분무공학회지
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• 제7권4호
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• pp.1-8
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• 2002

This paper investigates the spray angle and the outline shape of the liquid sheet discharged from a simplex swirl nozzle. A theoretical model was proposed and the corresponding experimental data were presented for comparison. Axial and tangential velocities and thickness of the liquid sheet at the nozzle exit were also predicted. The liquid sheet thickness at nozzle exit, as well as the discharge coefficient, turned out to be a sole function of the swirl Reynolds number. However, the axial and tangential velocities at nozzle exit and the spray angle could not be expressed only with the swirl Reynolds number. The predicted outline shape and spray angle of the liquid sheet agreed reasonably with the measured data.

• 한국분무공학회지
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• 제8권3호
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• pp.27-32
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• 2003

It is important to improve the efficiency of the existing small scale burner which used in agricultural product dry system and gardening dry system. In order to economize fuel Consumption and decrease the exhaust emission especially $CO_2$, the better design for the small scale burner is needed. Spray characteristics are the essential element for the design. Macroscopic spray characteristics such as spray angle and breakup length were measured. SMD which is contained the Microscopic spray characteristics was measured too. SMD was measured at 8mm, I2mm, I6mm downstream of the nozzle tip for both Hago and Danfoss nozzles by the Malvern Particle Sizer.

• 대한기계학회논문집B
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• 제28권1호
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• pp.109-117
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• 2004

The objective of this study is to investigate the effect of the spray characteristics on the etching characteristics for the optimization of etching process in the micro fabrication industry. The etching characteristics such as etching rate and etching factor were investigated under different etching conditions. To compare with the etching characteristic, the spray characteristics such as droplet size and velocity were measured by PDA system. The etching rate was increased in case of high spray pressure and in the region of spray center. The etching factor was increased with decrease in the distance from nozzle tip and increase in the etchant temperature. It was found that the spray characteristics were correlated with the etching characteristics.

• Journal of Advanced Marine Engineering and Technology
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• 제28권3호
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• pp.466-474
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• 2004

The characteristics of liquefied butane spray are expected to be different from conventional diesel fuel spray, because a flash boiling spray is expected when the surround pressure is below the saturated vapor pressure of the butane(0.23MPa 98K). The axial velocities. radial velocities. and size distributions in butane sprays were measured with PDPA(Phase Doppler Particle Analyzer) system. Sprays were macroscopically observed by using the high speed camera in case that the surround pressure is 0.37MPa and 0.15MPa. respectively. Compared with the conventional spray. the reversed results were investigated when the surround pressure is below the saturated vapor pressure of the butane.

• 대한기계학회논문집
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• 제19권2호
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• pp.548-558
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• 1995

An experimental investigation has been conducted to study the spray and combustion characteristics using the air-assisted twin fluid atomizer. Axial mean and fluctuating velocity components as well as drop-size distributions in non-reaction spray were measured with a nonintrusive phase doppler technique. Droplet number density distributions were also visualized using high speed CCD camera. Locations of spray and flame boundaries are obtained by direct photographic method. It is confirmed that at the fixed fuel flow rate, the increase of the atomizing air flow causes improvements on both spray and combustion characteristics under stable flame conditions. Internal group combustion modes where flame is located inside the spray boundary are observed to exist in the upstream region of higher droplet number density.