Water with a free surface in a water reservoir was pressurized by compressed air, and air was intentionally sucked into the liquid jet and ejected as a gas-liquid mixed jet from an abrupt contraction nozzle. We found that the droplets periodically protrude in radial direction from the jet caused by sucking air. So, this phenomenon is called Periodic Droplets Splashing Phenomena. Understanding the mechanism of droplet splash phenomenon may lead to the development of new droplet control technology. In a previous study, the effects of changing the nozzle length and diameter on droplet splashing were investigated, and it was found that the occurrence conditions and shape of droplet splash varied depending on the nozzle dimensions. In this study, the nozzle geometry was not changed, but only the dimensional magnification was changed in the similarity type, and radial velocity of splashing droplet, frequency of splashing droplet and thickness of droplet protrusion were observed as the effects of scale effect. The results showed that radial velocity of splashing droplet, frequency of splashing droplet and thickness of droplet protrusion varied with the nozzle scale, and that the scale was one of the factors controlling the periodic droplet splashing phenomenon.
Ishido et al. (Wed,) studied this question.