Condensation effect on high-speed liquid-film flow instability at a liquid-droplet impact on a solid surface in a vaporous environment

2016 Fiscal Year Final Research Report

• Project/Area Number: 26289031
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Fluid engineering
• Research Institution: Hokkaido University
• Principal Investigator: WATANABE MASAO 北海道大学, 工学(系)研究科(研究院), 教授 (30274484)
• Co-Investigator(Kenkyū-buntansha): 真田 俊之 静岡大学, 工学部, 准教授 (50403978) ; 小林 一道 北海道大学, 工学(系)研究科(研究院), 准教授 (80453140) ; 矢口 久雄 群馬工業高等専門学校, その他部局等, 講師 (20568521) ; 藤井 宏之 北海道大学, 工学(系)研究科(研究院), 助教 (00632580)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 流体 / 混相流 / 液滴 / 液滴衝突 / スプラッシュ / 薄膜流れ / 可視化

Outline of Final Research Achievements

Droplet impacts on solid surface are key elements in technical applications, such as rapid spray cooling, ink-jet printing and semiconductor cleaning. Although the broad varieties of parameters that control splash formation after the droplet impact, are proposed, they are not thoroughly explored; hence, dynamics of the droplet after the impact are yet fully understood. After droplet impacts on solid surface, characteristic film flow is developed; then splash may be generated. In this study, we examine the effects of the temperature of surrounding gas, which is either condensable or non-condensable, on ethanol droplet impact. We found that splash can be suppressed with the increase of the surrounding gas temperature. We measured the splash threshold pressure for a splash to appear as a function of the temperature. The results show that the splash threshold pressure is a monotonically increasing function of the surrounding gas temperature.

Free Research Field

流体力学