Laser-induced cavitation bubble interaction with surface-attached bubbles

Agrež, Vid (author), Lokar, Žiga (author), Petkovšek, Rok (author), Ohl, Claus-Dieter (author)

We study the interaction of laser-induced cavitation bubbles generated atop an electrode covered with hydrogen bubbles. The bubbles respond to the shock wave from laser-induced breakdown and the flow field of expanding and collapsing cavitation bubbles. High-speed imaging reveals that both the shock wave and subsequent flow contribute to bubble detachment and electrode clearance. Clearance occurs within an approximately circular area exceeding 3 times the maximum bubble radius, with partial clearance extending to 5 times this radius, which is considerably larger than reported for particulate or liquid contaminant removal. The initial shock wave propagates as a void fraction wave upon reaching the bubbles, producing radially propagating bubble disturbance with velocities ranging from 490 m/s at low bubble concentrations to 50 m/s at high concentrations. These speeds are within the range expected for linear waves in bubbly liquids according to Wood’s formula. Bubble removal persists for 10 ms, approximately 100 times longer than the cavitation bubble lifetime, which is attributed to long-lasting vortical flow generated by non-spherical cavitation bubble collapse. The findings may help to improve the removal of particulate contaminants as well as reducing ohmic loads in electrolyzers.

• Language: English
• Keywords: laser-induced cavitation, surface cleaning, bubble removal, shockwave, void fraction wave
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: 10 str.
• Numbering: Vol. 728, art. 166122
• PID: 20.500.12556/RUL-179049
• UDC: 532.528:544.537
• ISSN on article: 0169-4332
• DOI: 10.1016/j.apsusc.2026.166122
• COBISS.SI-ID: 267287299
• Publication date in RUL: 04.02.2026

Record is a part of a journal

• Title: Applied Surface Science
• Shortened title: Appl. surf. sci.
• Publisher: North-Holland
• ISSN: 0169-4332
• COBISS.SI-ID: 3283215

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: lasersko povzročena kavitacija, čiščenje površin, odstranjevanje mehurčkov, udarni valovi, val deleža praznin

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0270
• Name: Proizvodni sistemi, laserske tehnologije in spajanje materialov

• Funder: Other - Other funder or multiple funders
• Funding programme: Deutsche Forschungsgemeinschaft
• Project number: ME 1645/12-1