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Microbubble Generation via Combined Saffman-Taylor and Plateau-Rayleigh Instabilities
Citation
Cook, S and Barbaca, L and Russell, PS and Venning, JA and Pearce, BW and Brandner, PA, Microbubble Generation via Combined Saffman-Taylor and Plateau-Rayleigh Instabilities, Proceedings of the 23rd Australasian Fluid Mechanics Conference, 04-08 December 2022, Sydney, pp. AFMC2022-273. ISSN 2653-0597 (2022) [Refereed Conference Paper]
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Official URL: http://www.afms.org.au/proceedings/23.html
Abstract
Microbubble generation via rapid depressurization of supersaturated water through a 8 mm wide by 2
mm long by 0.1 mm deep Hele-Shaw passage was explored experimentally using micro shadowgraphy.
The flow topology consists of a series of regularly sized cellular cavities, characteristic of
viscous fingering in a Hele-Shaw flow. Cells develop in a region of separated flow at the sharp
leading edge of the confined flow. Each cell is stable and pinned to the wall. Small-scale
structures stretch into ligaments downstream and destabilise due to Plateau-Rayleigh instability,
with consequent microbubble pinch-off providing a coherent bubble stream from each cell. The
influence of cavitation number (σin j) and Reynolds number (Re) on instability formation and
microbubble production is investigated by varying the differential pressure between the passage
inlet and outlet. Optimum conditions for
bubble generation were found for σinj = 0.28 − 0.65 and coincide with the maximum in the number of
cells forming along the passage leading edge. Polydisperse bubble populations were generated for
all conditions. Bubble production rates of up to 2.2 MHz were observed, with a dominant bubble size
of ≈ 6µm. Further decrease in σinj hindered bubble generation due to disappearance of the laminar
instability as the flow in the passage transitions to a turbulent regime.
Item Details
| Item Type: | Refereed Conference Paper |
|---|---|
| Keywords: | microbubble generation, microfluidics, nuclei, Hele-Shaw cell |
| Research Division: | Engineering |
| Research Group: | Maritime engineering |
| Research Field: | Ship and platform structures (incl. maritime hydrodynamics) |
| Objective Division: | Expanding Knowledge |
| Objective Group: | Expanding knowledge |
| Objective Field: | Expanding knowledge in engineering |
| UTAS Author: | Cook, S (Miss Sienna Cook) |
| UTAS Author: | Barbaca, L (Dr Luka Barbaca) |
| UTAS Author: | Russell, PS (Mr Patrick Russell) |
| UTAS Author: | Venning, JA (Dr James Venning) |
| UTAS Author: | Pearce, BW (Dr Bryce Pearce) |
| UTAS Author: | Brandner, PA (Professor Paul Brandner) |
| ID Code: | 154809 |
| Year Published: | 2022 |
| Deposited By: | NC Maritime Engineering and Hydrodynamics |
| Deposited On: | 2023-01-09 |
| Last Modified: | 2023-01-16 |
| Downloads: | 0 |
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