In this study, an effervescent atomizer capable of mixing and spraying vegetable oil and kerosene at the same time was proposed to examine the usefulness of vegetable oil and kerosene in terms of recycling of renewable energy and waste resources. The effect of nozzle exit diameter variation on the atomization characteristics such as spray angle, droplet size distribution, cumulative volume distribution, and SMD was investigated using LDPA. The results of this study showed that the spray angles decreased with increasing ALR at the same nozzle exit diameter and increased with increasing nozzle exit diameter under the same ALR condition. SMD was decreased with increasing ALR at all nozzle exit diameters, and SMD was decreased with decreasing nozzle exit diameter even under the same ALR conditions. Also, the droplet was more finely atomized when the nozzle exit diameter is reduced under the same ALR conditions and when the ALR is increased at the same nozzle exit diameter, but the uniformity of the droplets was lowered because the droplet with a larger diameter existed.

To fabricate the 5182 aluminum-polymer sandwich panels, the strength of 5182 aluminum panels, which are the skin sheets that constitutes the sandwich composite panels, is changed according to the degree of heat treatment after rolling, and the characteristics of sandwich panel are also changed. In addition, in the stress-strain curves of the sandwich panel, the serration behavior observed in the 5182 aluminum alloy sheet is also observed. This serration behavior causes surface roughness during sheet forming, which is a serious problem in application to automotive body sheet. In this study, the tensile properties of the 5182 aluminum sandwich panels at room and elevated temperature were carefully investigated by tensile test. It can be found that when the aluminum surface sheets having insufficient heat treatment time is applied, the serration behavior does not completely disappear from the temperature of the room temperature to 160℃.

In order to apply rotary atomizer to agricultural spraying system, the motor direct coupled rotary atomizer was proposed. The effect of operating conditions such as atomizing air flow rate, working fluid flow rate, and rotation speed of spinning cup on the atomization performance was investigated for the proposed direct coupled rotary atomizer. The motor speed was controlled in the range of 6,000 to 12,000 rpm using an alternating current transformer, and the atomizing air was supplied by the compressor. In this study, LDPA was used to analyze the spray characteristics of the rotary atomizer. The representative particle diameters of D10, SMD, MMD, D90, and DMax tended to decrease as the atomizing air flow rate and the motor speed increased, but increased as the working fluid flow rate increased. Also, SMD was found to be influenced by order of atomizing air flow rate> motor speed> working fluid flow rate, and DMax was influenced by order of operating fluid supply> motor speed> atomizing air flow rate.