TY - JOUR
T1 - Crown formation from a cavitating bubble close to a free surface
AU - Saade, Youssef
AU - Jalaal, Maziyar
AU - Prosperetti, Andrea
AU - Lohse, Detlef
N1 - Funding Information:
The research leading to these results has received funding from the European Union's Horizon 2020 Research and Innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 813766. This work was carried out on the national e-infrastructure of SURFsara, a subsidiary of the SURF cooperation, the collaborative ICT organization for Dutch education and research.
Publisher Copyright:
© Authors 2021
PY - 2021/11/10
Y1 - 2021/11/10
N2 - A rapidly growing bubble close to a free surface induces jetting: a central jet protruding outwards and a crown surrounding it at later stages. While the formation mechanism of the central jet is known and documented, that of the crown remains unsettled. We perform axisymmetric simulations of the problem using the free software program BASILISK, where a finite-volume compressible solver has been implemented, which uses a geometric volume-of-fluid (VoF) method for the tracking of the interface. We show that the mechanism of crown formation is a combination of a pressure distortion over the curved interface, inducing flow focusing, and of a flow reversal, caused by the second expansion of the toroidal bubble that drives the crown. The work culminates in a parametric study with the Weber number, the Reynolds number, the pressure ratio and the dimensionless bubble distance to the free surface as control parameters. Their effects on both the central jet and the crown are explored. For high Weber numbers, we observe the formation of weaker 'secondary crowns', highly correlated with the third oscillation cycle of the bubble.
AB - A rapidly growing bubble close to a free surface induces jetting: a central jet protruding outwards and a crown surrounding it at later stages. While the formation mechanism of the central jet is known and documented, that of the crown remains unsettled. We perform axisymmetric simulations of the problem using the free software program BASILISK, where a finite-volume compressible solver has been implemented, which uses a geometric volume-of-fluid (VoF) method for the tracking of the interface. We show that the mechanism of crown formation is a combination of a pressure distortion over the curved interface, inducing flow focusing, and of a flow reversal, caused by the second expansion of the toroidal bubble that drives the crown. The work culminates in a parametric study with the Weber number, the Reynolds number, the pressure ratio and the dimensionless bubble distance to the free surface as control parameters. Their effects on both the central jet and the crown are explored. For high Weber numbers, we observe the formation of weaker 'secondary crowns', highly correlated with the third oscillation cycle of the bubble.
KW - cavitation
KW - Bubble dynamics
KW - UT-Hybrid-D
UR - http://www.scopus.com/inward/record.url?scp=85114452427&partnerID=8YFLogxK
U2 - 10.1017/jfm.2021.676
DO - 10.1017/jfm.2021.676
M3 - Article
AN - SCOPUS:85114452427
SN - 0022-1120
VL - 926
JO - Journal of fluid mechanics
JF - Journal of fluid mechanics
M1 - A5
ER -