Marangoni convection instabilities in an evaporating droplet on a non-isothermal substrate
The Marangoni convection instabilities are investigated in a sessile ethanol droplet as it evaporates on a non-isothermal substrate. The instability structures consistently, preferentially occur at the lower temperature side of substrate. Drifted by the azimuthal thermocapillary flow under externall...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2022
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| Subjects: | |
| Online Access: | https://hdl.handle.net/10356/161771 |
| _version_ | 1811686505101393920 |
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| author | Wang, Tian-Shi Shi, Wan-Yuan Duan, Fei |
| author2 | School of Mechanical and Aerospace Engineering |
| author_facet | School of Mechanical and Aerospace Engineering Wang, Tian-Shi Shi, Wan-Yuan Duan, Fei |
| author_sort | Wang, Tian-Shi |
| collection | NTU |
| description | The Marangoni convection instabilities are investigated in a sessile ethanol droplet as it evaporates on a non-isothermal substrate. The instability structures consistently, preferentially occur at the lower temperature side of substrate. Drifted by the azimuthal thermocapillary flow under externally imposed temperature gradient, the longitudinal rolls are found to propagate from the hot side to the cold side for the droplet, while a radial propagation of the BM cells directly from the cold side to the hot side along the droplet diameter occurs at the last period of evaporation process. The azimuthal propagation speed of longitudinal rolls increases with the increase of temperature gradient, but is independent of the mean temperature of the substrate. Effects of the mean temperature of substrate and the temperature gradient on the Marangoni instabilities are investigated, and the critical conditions for the onset of longitudinal rolls are determined. |
| first_indexed | 2024-10-01T05:01:29Z |
| format | Journal Article |
| id | ntu-10356/161771 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T05:01:29Z |
| publishDate | 2022 |
| record_format | dspace |
| spelling | ntu-10356/1617712022-09-19T08:19:19Z Marangoni convection instabilities in an evaporating droplet on a non-isothermal substrate Wang, Tian-Shi Shi, Wan-Yuan Duan, Fei School of Mechanical and Aerospace Engineering Engineering::Mechanical engineering Marangoni Convection Evaporation The Marangoni convection instabilities are investigated in a sessile ethanol droplet as it evaporates on a non-isothermal substrate. The instability structures consistently, preferentially occur at the lower temperature side of substrate. Drifted by the azimuthal thermocapillary flow under externally imposed temperature gradient, the longitudinal rolls are found to propagate from the hot side to the cold side for the droplet, while a radial propagation of the BM cells directly from the cold side to the hot side along the droplet diameter occurs at the last period of evaporation process. The azimuthal propagation speed of longitudinal rolls increases with the increase of temperature gradient, but is independent of the mean temperature of the substrate. Effects of the mean temperature of substrate and the temperature gradient on the Marangoni instabilities are investigated, and the critical conditions for the onset of longitudinal rolls are determined. This work was supported by National Natural Science Foundation of China (No. 51676018). Thanks for the financial support from the program of China Scholarships Council (No. 202006050147). 2022-09-19T08:19:19Z 2022-09-19T08:19:19Z 2022 Journal Article Wang, T., Shi, W. & Duan, F. (2022). Marangoni convection instabilities in an evaporating droplet on a non-isothermal substrate. International Journal of Heat and Mass Transfer, 195, 123140-. https://dx.doi.org/10.1016/j.ijheatmasstransfer.2022.123140 0017-9310 https://hdl.handle.net/10356/161771 10.1016/j.ijheatmasstransfer.2022.123140 2-s2.0-85132385567 195 123140 en International Journal of Heat and Mass Transfer © 2022 Elsevier Ltd. All rights reserved. |
| spellingShingle | Engineering::Mechanical engineering Marangoni Convection Evaporation Wang, Tian-Shi Shi, Wan-Yuan Duan, Fei Marangoni convection instabilities in an evaporating droplet on a non-isothermal substrate |
| title | Marangoni convection instabilities in an evaporating droplet on a non-isothermal substrate |
| title_full | Marangoni convection instabilities in an evaporating droplet on a non-isothermal substrate |
| title_fullStr | Marangoni convection instabilities in an evaporating droplet on a non-isothermal substrate |
| title_full_unstemmed | Marangoni convection instabilities in an evaporating droplet on a non-isothermal substrate |
| title_short | Marangoni convection instabilities in an evaporating droplet on a non-isothermal substrate |
| title_sort | marangoni convection instabilities in an evaporating droplet on a non isothermal substrate |
| topic | Engineering::Mechanical engineering Marangoni Convection Evaporation |
| url | https://hdl.handle.net/10356/161771 |
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