エタノール液滴のスプラッシュ発生に及ぼす蒸気の凝縮効果

抄録

The present study aims to experimentally and numerically investigate the effect of vapor condensation on the splash generation mechanism after droplet impact. First, we experimentally observed ethanol droplet impact in a vacuum chamber in air or ethanol vapor. At the same ambient pressure, the splash was suppressed in ethanol vapor. We considered the cause of the difference in the two results to be vapor condensation. Next, we numerically simulated the droplet impact with or without vapor condensation. The results show that when the droplet impacts, the ambient pressure with condensation near the impact point becomes lower than that without condensation. Finally, we investigated the influence of condensation coefficient on the ambient pressure of vapor near the impact point. From the results, as the value of condensation coefficient increases, the ambient gas pressure after the impact decreases. We concluded that the vapor condensation suppresses the generation of splash after droplet impact.