• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.3
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• pp.128-136
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• 1997

Spray characteristics of a fuel injector have an important effect upon engine power and emission. Thus this study was investigated the spray characteristics of the intermittent injection using a gasoline fuel injector. Image processing system and PDA system were utilized for visualization of a spray behavior and measurements of a droplet size and velocity, respectively. Fuel injection duration was fixed with 3ms and injection pressure was varied such as 250kPa, 300kPa, 350kPa. for a high fuel injection pressure, spray tip arrival time was fluctuated at a vigorously disintegrated cross section. Axial velocity was linear correlated with fuel droplet size in the time interval of an injected main spray at spray downstream.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.5
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• pp.66-71
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• 2011

The spray distribution at high pressure condition was measured by the Tomography method. The constructed spray distribution was compared with the images by Indirect Photography method so that the spray size confirmed and took the boundary of the distribution. It confirmed that the Tomography applies to construct the distribution at high pressure.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.11
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• pp.3021-3031
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• 1994

Experiments have been performed to find out the effect of the mixing port length of Y-jet atomizers on the spray performance, using air and water as the test fluids. Water and air flow rates and drop sizes were measured at each injection pressure condition for different mixing port length. The air flow rate was almost unaffected by the change of the mixing port length. However, the water flow rate was relatively susceptible to the change of the mixing port length. The mixing point pressure was very much influenced by the mixing port length. Variations of spatial distribution of Sauter Mean Diameter (SMD, $D_{32}$) and the cross-section-averaged SMD ($D_{32,m}$) with different mixing port length and air/water mass flow rate ratio were examined. Generally, when the mixing port length was reduced, the mean drop size decreased and became spatially even.

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.745-752
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• 1996

Wear property of plasma spray coating in $Cr_2O_3$ powder manufatured of spray dry method on the aluminum substrate was inspected for the application of piston-ring of automotive enginel. The plama spray coatings were varied with feed rate and particle size. Used the ball-on disc type tribometer, wear volume, friction, surface rougness were investigated. The delamination of the coating layer were observed with SEM. Also the cross-section of wear track were investigated, using optical microscopy. As a result of experiment, wear mechanism was addressed in the various coating process.

• Journal of Sericultural and Entomological Science
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• v.40 no.2
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• pp.143-149
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• 1998

For the application of silk sericin, silk sericin powders were prepared by various spray dry conditions and the characteristics of silk sericin/polyurethane mixed films were investigated. When the sericin was dried from the solution at higher inlet and outlet temperature, larger sizes of the powder particles were obtained. It was also found that inlet and outlet temperatures were important factors affecting the shape and surface characteristics of sericin power particle. The many holes and empty spaces were observed at the surface and cross section of sericin/PU mixed film. With the increase of the amount of sericin powder in the mixed films, the size and number of holes and empty spaces were increased. The thickness of sericin/PU mixed film was increased with the content of sericin powder. As the portion of sericin powder increase, the tenacity is decreased while the elongation slightly increased.