Experimental Study of Bubble Formation from a Micro-Tube in Non-Newtonian Fluid
Over the last few years, microbubbles have found application in biomedicine. In this study, the characteristics of bubbles formed when air is introduced from a micro-tube (internal diameter 110 μm) in non-Newtonian shear thinning fluids are studied. The dependence of the release time and the size of...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-01-01
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| Series: | Micromachines |
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| Online Access: | https://www.mdpi.com/2072-666X/12/1/71 |
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| author | Georgia Kontaxi Yorgos G. Stergiou Aikaterini A. Mouza |
| author_facet | Georgia Kontaxi Yorgos G. Stergiou Aikaterini A. Mouza |
| author_sort | Georgia Kontaxi |
| collection | DOAJ |
| description | Over the last few years, microbubbles have found application in biomedicine. In this study, the characteristics of bubbles formed when air is introduced from a micro-tube (internal diameter 110 μm) in non-Newtonian shear thinning fluids are studied. The dependence of the release time and the size of the bubbles on the gas phase rate and liquid phase properties is investigated. The geometrical characteristics of the bubbles are also compared with those formed in Newtonian fluids with similar physical properties. It was found that the final diameter of the bubbles increases by increasing the gas flow rate and the liquid phase viscosity. It was observed that the bubbles formed in a non-Newtonian fluid have practically the same characteristics as those formed in a Newtonian fluid, whose viscosity equals the asymptotic viscosity of the non-Newtonian fluid, leading to the assumption that the shear rate around an under-formation bubble is high, and the viscosity tends to its asymptotic value. To verify this notion, bubble formation was simulated using Computational Fluid Dynamics (CFD). The simulation results revealed that around an under-formation bubble, the shear rate attains a value high enough to lead the viscosity of the non-Newtonian fluid to its asymptotic value. |
| first_indexed | 2024-03-09T05:10:08Z |
| format | Article |
| id | doaj.art-78139ba2ffd94495beb021bc48259f38 |
| institution | Directory Open Access Journal |
| issn | 2072-666X |
| language | English |
| last_indexed | 2024-03-09T05:10:08Z |
| publishDate | 2021-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj.art-78139ba2ffd94495beb021bc48259f382023-12-03T12:50:06ZengMDPI AGMicromachines2072-666X2021-01-011217110.3390/mi12010071Experimental Study of Bubble Formation from a Micro-Tube in Non-Newtonian FluidGeorgia Kontaxi0Yorgos G. Stergiou1Aikaterini A. Mouza2Chemical Engineering Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, GreeceChemical Engineering Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, GreeceChemical Engineering Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, GreeceOver the last few years, microbubbles have found application in biomedicine. In this study, the characteristics of bubbles formed when air is introduced from a micro-tube (internal diameter 110 μm) in non-Newtonian shear thinning fluids are studied. The dependence of the release time and the size of the bubbles on the gas phase rate and liquid phase properties is investigated. The geometrical characteristics of the bubbles are also compared with those formed in Newtonian fluids with similar physical properties. It was found that the final diameter of the bubbles increases by increasing the gas flow rate and the liquid phase viscosity. It was observed that the bubbles formed in a non-Newtonian fluid have practically the same characteristics as those formed in a Newtonian fluid, whose viscosity equals the asymptotic viscosity of the non-Newtonian fluid, leading to the assumption that the shear rate around an under-formation bubble is high, and the viscosity tends to its asymptotic value. To verify this notion, bubble formation was simulated using Computational Fluid Dynamics (CFD). The simulation results revealed that around an under-formation bubble, the shear rate attains a value high enough to lead the viscosity of the non-Newtonian fluid to its asymptotic value.https://www.mdpi.com/2072-666X/12/1/71microfluidicsbubblesnon-Newtonian fluidsCFD |
| spellingShingle | Georgia Kontaxi Yorgos G. Stergiou Aikaterini A. Mouza Experimental Study of Bubble Formation from a Micro-Tube in Non-Newtonian Fluid Micromachines microfluidics bubbles non-Newtonian fluids CFD |
| title | Experimental Study of Bubble Formation from a Micro-Tube in Non-Newtonian Fluid |
| title_full | Experimental Study of Bubble Formation from a Micro-Tube in Non-Newtonian Fluid |
| title_fullStr | Experimental Study of Bubble Formation from a Micro-Tube in Non-Newtonian Fluid |
| title_full_unstemmed | Experimental Study of Bubble Formation from a Micro-Tube in Non-Newtonian Fluid |
| title_short | Experimental Study of Bubble Formation from a Micro-Tube in Non-Newtonian Fluid |
| title_sort | experimental study of bubble formation from a micro tube in non newtonian fluid |
| topic | microfluidics bubbles non-Newtonian fluids CFD |
| url | https://www.mdpi.com/2072-666X/12/1/71 |
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