Surface functionalization by nanosecond-laser texturing for controlling hydrodynamic cavitation dynamics

Petkovšek, Martin (author), Hočevar, Matej (author), Gregorčič, Peter (author)

The interaction between liquid flow and solid boundary can result in cavitation formation when the local pressure drops below vaporization threshold. The cavitation dynamics does not depend only on basic geometry, but also on surface roughness, chemistry and wettability. From application point of view, controlling cavitation in fluid flows by surface functionalization is of great importance to avoid the unwanted effects of hydrodynamic cavitation (erosion, noise and vibrations). However, it could be also used for intensification of various physical and chemical processes. In this work, the surfaces of 10-mm stainless steel cylinders are laser textured in order to demonstrate how hydrodynamic cavitation behavior can be controlled by surface modification. The surface properties are modified by using a nanosecond (10-28 ns) fiber laser (wavelength of 1060 nm). In such a way, surfaces with different topographies and wettability were produced and tested in a cavitation tunnel at different cavitation numbers (1.0-2.6). Cavitation characteristics behind functionalized cylindrical surfaces were monitored simultaneously by high-speed visualization (20,000 fps) and high frequency pressure transducers. The results clearly show that cavitation characteristics differ significantly between different micro-structured surfaces. On some surfaces incipient cavitation is delayed and cavitation extent decreased in comparison with the reference - a highly polished cylinder. It is also shown that the increased surface wettability (i.e., hydrophilicity) delays the incipient cavitation.

• Language: English
• Keywords: hydrodynamic cavitation, laser surface engineering, fluid dynamics, laser texturing, surface engineering, hydrophobic/hydrophilic surface
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2020
• Number of pages: 10 str.
• Numbering: Vol. 67, art. 105126
• PID: 20.500.12556/RUL-116529
• UDC: 532.5(045)
• ISSN on article: 1350-4177
• DOI: 10.1016/j.ultsonch.2020.105126
• COBISS.SI-ID: 17154075
• Publication date in RUL: 27.05.2020

Record is a part of a journal

• Title: Ultrasonics Sonochemistry
• Shortened title: Ultrason. sonochem.
• Publisher: Butterworth-Heinemann, Elsevier Science
• ISSN: 1350-4177
• COBISS.SI-ID: 707668

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: hidrodinamska kavitacija, laserski inženiring površin, dinamika fluidov, laserske obdelave, inženiring površin, hidrofobna/hidrofilna površina