• Journal of ILASS-Korea
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• v.6 no.4
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• pp.39-48
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• 2001

The Gasoline Direct Injection(GDI) system has been highlighted due to the improvement of fuel consumption and the control of exhaust emission from gasoline engines. Main purpose of the present study is to measure spray characteristics of GDSI for real engine application. We have investigated experimentally spray tip penetration, spray angle, tip velocity and spatial spray distribution. Counter-rotating vortex grown on the spray surface plays an important role in the spray characteristics. Accordingly the spray tip penetration and tip velocity do not excess 50mm, 20m/s respectively, under 0.6MPa ambient pressure. the spray cone angle of GDSI have a same tendency to a simplex swirl atomizer.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.186-190
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• 2006

This study was performed to investigate the characteristics of a co-axial swirl injector. Especially to predict the initial liquid sheet thickness and spray cone angle of an outer orifice a concept of effective area was introduced from hydraulic analysis. In addition, the parameters determining the characteristics of a co-axial swirl injector were re-defined around outer orifice. The calculated results-SMD, spray cone angle, and spray thickness agreed well with the test results qualitatively.

• Journal of Biosystems Engineering
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• v.10 no.1
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• pp.13-23
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• 1985

Spraying method from the paddy-field levee is known to give insufficient penetration of the spray droplets to the rice stem of the densely grown plants, which is generally encountered at the last stage of rice growth. This study was intended to investigate the spraying system to solve this existing problem. As an approach, it was attempted to develop the boom-with-nozzle, between-the-row application system. Several types of nozzles and their different arrangements in the boom were tested in the field to measure the penetration-reaching distance and the uniformity of spray droplet distribution. The results of the study are summarized as follows: 1. Field experiments by the spraying method from the paddy-field levee showed to have practically no penetration of the spray droplets to the portion of the plant stem with the normal flow volume generally applied and thus need for improving present spraying method. 2. It was found that, considering both the uniformity of the spray droplet distribution and performance rate, the most efficient type of nozzle in the between-the-row boom-type spraying system was one that has core-insert hollow-cone with some clearance between the cone and tip. 3. When tested by applying the spraying method of between-the-row, the nozzle pressure did not affect the uniformity of spray droplet distribution. However, the nozzle pressure had a positive effect on the penetrating-reaching distance of the facing side of the rice stem and did not affect much on that of the opposite face of the stem. It was also found that the maximum pressure to affect the penetration-reaching distance was about $10kg/cm^2$. 4. The uniformity of the spray droplet distribution in the between-the-row system was greatly affected by the height and orientation of the nozzles in the boom. Based on experimental work for the different type of the boom-with-nozzle arrangements, it is recommended that the position of nozzle is set at about 0.45 m above the ground and two nozzles in the boom are oriented to be faced with each other with some angle such that the droplet stream from the nozzle would not directly face with each other.

• Journal of the korean Society of Automotive Engineers
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• v.15 no.1
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• pp.37-44
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• 1993

Fuel injection system is an important tool in the exhaust emission and performance of a diesel engine. Effects of the fuel injection system in diesel combustion was investigated experimentally by measuring the performance and analyzing the combustion phenomena in a D.I. diesel engine. The selected injection parameters were nozzle opening pressure, nozzle projection length, and nozzle spray angle. From the measured results, it is shown that the fuel injection pipe diameter is an effective means to improve engine performance in a middle and high speed range and the 2 stage spring nozzle holder has the advantage of increasing the engine performance due to the initial injection pressure in a low speed range. It has been also shown that increasing nozzle opening pressure resulted in decrease in smoke, but increase in NO$_{x}$ from the engine.e.