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

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

Povzetek

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.

Ključne besede

hydrodynamic cavitation;laser surface engineering;fluid dynamics;laser texturing;

Podatki

Jezik:	Angleški jezik
Leto izida:	2020
Tipologija:	1.01 - Izvirni znanstveni članek
Organizacija:	UL FS - Fakulteta za strojništvo
UDK:	532.5(045)
COBISS:	17154075
ISSN:	1350-4177
Št. ogledov:	792
Št. prenosov:	576
Ocena:	0 (0 glasov)
Metapodatki:

Ostali podatki

Sekundarni jezik:	Slovenski jezik
Sekundarne ključne besede:	hidrodinamska kavitacija;laserski inženiring površin;dinamika fluidov;laserske obdelave;
Vrsta dela (COBISS):	Članek v reviji
Strani:	str. 1-10
Zvezek:	ǂVol. ǂ67
Čas izdaje:	2020
DOI:	10.1016/j.ultsonch.2020.105126
ID:	11752593