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Numerical estimation of critical local energy dissipation rate for particle detachment from a bubble-particle aggregate captured within a confined vortex.
- Source :
-
Minerals Engineering . Apr2022, Vol. 180, pN.PAG-N.PAG. 1p. - Publication Year :
- 2022
-
Abstract
- [Display omitted] • Interaction of a bubble-particle aggregate with a confined vortex investigated. • An interface resolved 3D CFD model developed to quantify the interaction dynamics. • Highspeed shadowgraphy and PIV experiments performed to validate the CFD model. • Correlation of vorticity and local energy dissipation rate (ε) determined from CFD model. • A force-balance model used to predict particle detachment using ε. In flotation, interactions of bubble-particle aggregates with turbulent flow structures in the liquid medium result in particle detachment. This study aims to simulate this phenomenon involving a bubble-particle aggregate (bubble diameter ∼ 3 mm and particle diameter ∼ 314 µm) interacting with a turbulent flow structure manifested as a confined vortex in a square cavity connected to a square cross-section channel. An interface resolved three dimensional (3D) computational fluid dynamics (CFD) model was developed to quantify the bubble-vortex interaction dynamics over a range of channel Reynolds numbers. The CFD model produced a good agreement with the experimentally measured vorticity magnitude, local energy dissipation rate, and bubble motion. It was shown that a bubble-particle aggregate could be captured within the vortex by suitably varying the channel Reynolds number, eventually leading to particle detachment. A separate force balance analysis was performed to determine a criterion for particle detachment utilising the CFD model predicted vorticity and local energy dissipation rate. It was shown that a critical local energy dissipation rate ∼ 1.59 m2/s3 was required for particle detachment to occur, which was also verified experimentally. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 08926875
- Volume :
- 180
- Database :
- Academic Search Index
- Journal :
- Minerals Engineering
- Publication Type :
- Academic Journal
- Accession number :
- 155962636
- Full Text :
- https://doi.org/10.1016/j.mineng.2022.107508