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

• 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
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥16,770,000 (Direct Cost: ¥12,900,000、Indirect Cost: ¥3,870,000); Fiscal Year 2016: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000); Fiscal Year 2015: ¥5,850,000 (Direct Cost: ¥4,500,000、Indirect Cost: ¥1,350,000); Fiscal Year 2014: ¥8,710,000 (Direct Cost: ¥6,700,000、Indirect Cost: ¥2,010,000)
• 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 / 熱工学 / マイクロ・ナノデバイス / 流体力学

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.

Research Products

• [Journal Article] 円形平板への液滴列衝突による形成液膜の観察 (2017)
  • Author(s): 村木 駿介，山本 翔也，真田 俊之，渡部 正夫
  • Journal Title: 日本機械学会論文集 Volume: 83
  • NAID: 130005612201
  • Peer Reviewed / Open Access / Acknowledgement Compliant
• [Journal Article] Early stage of nanodroplet impact on solid wall (2016)
  • Author(s): 1.Kazumichi Kobayashi, Kazuki Konno, Hisao Yaguchi, Hiroyuki Fujii, Toshiyuki Sanada and Masao Watanabe
  • Journal Title: Physics of fluids Volume: 28 Issue: 3 Pages: 1-10
  • DOI: 10.1063/1.4942874
  • NAID: 120005712515
  • Peer Reviewed / Open Access
• [Journal Article] 低圧力環境下での高速液滴衝突により発生する液膜流れ (2015)
  • Author(s): 加藤雅也，渡部正夫，小林一道，真田俊之
  • Journal Title: 混相流 Volume: 28 Pages: 531-537
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] Observation of non-spherical droplet impacts with velocities of O(10 m/s) (2016)
  • Author(s): Yutaka Kataoka, Yuusaku Hori, Masao Watanabe, Kazumichi Kobayashi, Hiroyuki Fujii,Toshiyuki Sanada
  • Organizer: 9th International Conference on Multiphase Flow
  • Place of Presentation: Firenze, Italy
  • Year and Date: 2016-05-22
  • Int'l Joint Research
• [Presentation] Effects of surrounding gas temperature on ethanol droplet impact on solid surface (2016)
  • Author(s): Toshihisa Isono, Masao Watanabe, Kazumichi Kobayashi, Hiroyuki Fujii,Toshiyuki Sanada
  • Organizer: 9th International Conference on Multiphase Flow
  • Place of Presentation: Firenze, Italy
  • Year and Date: 2016-05-22
  • Int'l Joint Research