Mass transfer and modeling of deformed bubbles in square microchannel
Understanding of mass transfer in gas-liquid slug flow is imperative to design and optimize micro-reactors. There exist extensive studies on symmetric bubbles by the phase volume monitor technique, whereas deformed bubbles are rarely studied due to the limitation of volume calculation methods. In th...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2023-11-01
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| Series: | Chemical Engineering Journal Advances |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2666821123000753 |
| _version_ | 1797388693882798080 |
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| author | Shuo Yang Gaopan Kong Zhen Cao Zan Wu |
| author_facet | Shuo Yang Gaopan Kong Zhen Cao Zan Wu |
| author_sort | Shuo Yang |
| collection | DOAJ |
| description | Understanding of mass transfer in gas-liquid slug flow is imperative to design and optimize micro-reactors. There exist extensive studies on symmetric bubbles by the phase volume monitor technique, whereas deformed bubbles are rarely studied due to the limitation of volume calculation methods. In this work, CO2-water and N2-water two-phase flows were investigated in a square microchannel, obtaining annular flow, slug flow, and bubbly flow. A flow pattern map was then proposed and compared with the literature. A 3D slicing technique was developed to measure the volume and interfacial area of bubble, including symmetric bubbles and deformed bubbles, by slicing the bubble along the streamwise direction. Scaling laws of the important parameters that characterize the micro-reactors were proposed. Mass transfer coefficients kLa were quantified from the time-changing volume. The empirical correlation involving dimensionless numbers were fitted, which shows accurate predictive performance for mass transfer coefficients in this study and literatures. The bigger index of Reynolds number ReG indicated that gas flow condition is the main influencing factor during mass transfer process. To have a better universality, a new semi-theoretical model involving the ratio of the size of the liquid and gas phases LL/LG was developed based on the Pigford and Higbie penetration theory because experimental data confirms that the degree of bubble deformation is related to LL/LG. The semi-theoretical model shows a satisfactory agreement over the whole range of slug flow in this study. |
| first_indexed | 2024-03-08T22:44:31Z |
| format | Article |
| id | doaj.art-a8aed2d6fcb0449eacc9fd0864a8b8fa |
| institution | Directory Open Access Journal |
| issn | 2666-8211 |
| language | English |
| last_indexed | 2024-03-08T22:44:31Z |
| publishDate | 2023-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Chemical Engineering Journal Advances |
| spelling | doaj.art-a8aed2d6fcb0449eacc9fd0864a8b8fa2023-12-17T06:42:06ZengElsevierChemical Engineering Journal Advances2666-82112023-11-0116100518Mass transfer and modeling of deformed bubbles in square microchannelShuo Yang0Gaopan Kong1Zhen Cao2Zan Wu3Department of Energy Sciences, Lund University, Lund, SE-22100, SwedenDepartment of Energy Sciences, Lund University, Lund, SE-22100, Sweden; Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, CB2 1QA, United KingdomDepartment of Energy Sciences, Lund University, Lund, SE-22100, SwedenZJU-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou, 311200, China; College of Electrical Engineering, Zhejiang University, Hangzhou, 310027, China; Corresponding author.Understanding of mass transfer in gas-liquid slug flow is imperative to design and optimize micro-reactors. There exist extensive studies on symmetric bubbles by the phase volume monitor technique, whereas deformed bubbles are rarely studied due to the limitation of volume calculation methods. In this work, CO2-water and N2-water two-phase flows were investigated in a square microchannel, obtaining annular flow, slug flow, and bubbly flow. A flow pattern map was then proposed and compared with the literature. A 3D slicing technique was developed to measure the volume and interfacial area of bubble, including symmetric bubbles and deformed bubbles, by slicing the bubble along the streamwise direction. Scaling laws of the important parameters that characterize the micro-reactors were proposed. Mass transfer coefficients kLa were quantified from the time-changing volume. The empirical correlation involving dimensionless numbers were fitted, which shows accurate predictive performance for mass transfer coefficients in this study and literatures. The bigger index of Reynolds number ReG indicated that gas flow condition is the main influencing factor during mass transfer process. To have a better universality, a new semi-theoretical model involving the ratio of the size of the liquid and gas phases LL/LG was developed based on the Pigford and Higbie penetration theory because experimental data confirms that the degree of bubble deformation is related to LL/LG. The semi-theoretical model shows a satisfactory agreement over the whole range of slug flow in this study.http://www.sciencedirect.com/science/article/pii/S2666821123000753Mass transferDigital image analysis3D reconstructionSlug flowMicrochannelScaling law |
| spellingShingle | Shuo Yang Gaopan Kong Zhen Cao Zan Wu Mass transfer and modeling of deformed bubbles in square microchannel Chemical Engineering Journal Advances Mass transfer Digital image analysis 3D reconstruction Slug flow Microchannel Scaling law |
| title | Mass transfer and modeling of deformed bubbles in square microchannel |
| title_full | Mass transfer and modeling of deformed bubbles in square microchannel |
| title_fullStr | Mass transfer and modeling of deformed bubbles in square microchannel |
| title_full_unstemmed | Mass transfer and modeling of deformed bubbles in square microchannel |
| title_short | Mass transfer and modeling of deformed bubbles in square microchannel |
| title_sort | mass transfer and modeling of deformed bubbles in square microchannel |
| topic | Mass transfer Digital image analysis 3D reconstruction Slug flow Microchannel Scaling law |
| url | http://www.sciencedirect.com/science/article/pii/S2666821123000753 |
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