Liquid Sterilization Using Collapse of Explosive Bubbles

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K14172
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Thermal engineering
• Research Institution: Yokohama National University
• Principal Investigator: Ishii Kazuhiro 横浜国立大学, 大学院工学研究院, 教授 (20251754)
• Co-Investigator(Kenkyū-buntansha): 片岡 秀文 大阪府立大学, 工学(系)研究科(研究院), 助教 (10548241)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 燃焼 / デトネーション / 衝撃波 / バブル

Outline of Final Research Achievements

An underwater shock wave was driven in water containing a stoichiometric ethylene-oxygen bubbles to study collapse of an explosive bubble and the subsequent shock wave generation. In addition, an underwater shock wave was driven in water containing air-microbubbles to study pressure gain. The following results have been obtained. 1) After passage of the underwater shock wave, the bubble starts to shrink, resulting in explosion just before reaching the minimum radius. In the bubble rebound phase a shock wave is generated whose strength is about twice that for the air bubble. 2) The maximum pressure of the shock is inversely proportional to the distance. 3) The microbubbles generally weaken the incident underwater shock wave, whose waveform changes into a sharp one. However, it is demonstrated that the microbubble addition makes the peak shock pressure 1.76 times higher than in the case without addition of microbubbles.

Free Research Field

燃焼工学