Flow transitions in collisions between vortex-rings and density interfaces
Flow transitions and vortical developments during vortex-ring collisions with a sharp water–oil density interface are studied using planar laser-induced fluorescence and time-resolved particle-image velocimetry techniques. Circular vortex-rings at Reynolds numbers of Re = 1000 , 2000 and 4000 collid...
| 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/10356/160898 |
| _version_ | 1811694083788242944 |
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| author | Yeo, Kye Wei B. Koh, J. Y. Long, J. New, Tze How |
| author2 | School of Mechanical and Aerospace Engineering |
| author_facet | School of Mechanical and Aerospace Engineering Yeo, Kye Wei B. Koh, J. Y. Long, J. New, Tze How |
| author_sort | Yeo, Kye Wei B. |
| collection | NTU |
| description | Flow transitions and vortical developments during vortex-ring collisions with a sharp water–oil density interface are studied using planar laser-induced fluorescence and time-resolved particle-image velocimetry techniques. Circular vortex-rings at Reynolds numbers of Re = 1000 , 2000 and 4000 colliding with a density interface characterized by an Atwood number of approximately A= 0.045 were investigated. Results show that at Re = 1000 , collision with the density interface produces vortical structures and flow transitions that are relatively similar to those for a solid-boundary collision. However, the dynamics underlying the present vortical formations and behaviour are different from those associated with solid-boundary collisions, in that the former are driven by baroclinic vorticity generation. Flow behaviour at Re = 2000 shows more significant deformation of the density interface by the vortex-ring but overall behaviour remains comparable. Last but not least, at Re = 4000 , the largest Reynolds number investigated here, the vortex-ring penetrates the density interface almost completely. However, buoyancy effects eventually limit its penetration and reverse its translational direction, such that it crosses back into the oil layer again with its vortex core rotational senses reversed as well. At the same time, vortex-ring fluid is shed and a significant trailing-jet is left in the former’s wake. |
| first_indexed | 2024-10-01T07:01:56Z |
| format | Journal Article |
| id | ntu-10356/160898 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T07:01:56Z |
| publishDate | 2022 |
| record_format | dspace |
| spelling | ntu-10356/1608982022-08-05T07:32:31Z Flow transitions in collisions between vortex-rings and density interfaces Yeo, Kye Wei B. Koh, J. Y. Long, J. New, Tze How School of Mechanical and Aerospace Engineering Engineering::Mechanical engineering Vortex-Ring Collision Flow transitions and vortical developments during vortex-ring collisions with a sharp water–oil density interface are studied using planar laser-induced fluorescence and time-resolved particle-image velocimetry techniques. Circular vortex-rings at Reynolds numbers of Re = 1000 , 2000 and 4000 colliding with a density interface characterized by an Atwood number of approximately A= 0.045 were investigated. Results show that at Re = 1000 , collision with the density interface produces vortical structures and flow transitions that are relatively similar to those for a solid-boundary collision. However, the dynamics underlying the present vortical formations and behaviour are different from those associated with solid-boundary collisions, in that the former are driven by baroclinic vorticity generation. Flow behaviour at Re = 2000 shows more significant deformation of the density interface by the vortex-ring but overall behaviour remains comparable. Last but not least, at Re = 4000 , the largest Reynolds number investigated here, the vortex-ring penetrates the density interface almost completely. However, buoyancy effects eventually limit its penetration and reverse its translational direction, such that it crosses back into the oil layer again with its vortex core rotational senses reversed as well. At the same time, vortex-ring fluid is shed and a significant trailing-jet is left in the former’s wake. Nanyang Technological University The authors acknowledge support for the present study by the School of Mechanical & Aerospace Engineering and CN Yang Scholars" Programme at Nanyang Technological University, Singapore. Funding provided for the first author to present this work at the 15th Asian Symposium on Visualization under a School of Mechanical & Aerospace Engineering Enrichment Grant is also gratefully acknowledged. 2022-08-05T06:46:20Z 2022-08-05T06:46:20Z 2020 Journal Article Yeo, K. W. B., Koh, J. Y., Long, J. & New, T. H. (2020). Flow transitions in collisions between vortex-rings and density interfaces. Journal of Visualization, 23(5), 783-791. https://dx.doi.org/10.1007/s12650-020-00666-7 1343-8875 https://hdl.handle.net/10356/160898 10.1007/s12650-020-00666-7 2-s2.0-85087635478 5 23 783 791 en Journal of Visualization © 2020 The Visualization Society of Japan. All rights reserved. |
| spellingShingle | Engineering::Mechanical engineering Vortex-Ring Collision Yeo, Kye Wei B. Koh, J. Y. Long, J. New, Tze How Flow transitions in collisions between vortex-rings and density interfaces |
| title | Flow transitions in collisions between vortex-rings and density interfaces |
| title_full | Flow transitions in collisions between vortex-rings and density interfaces |
| title_fullStr | Flow transitions in collisions between vortex-rings and density interfaces |
| title_full_unstemmed | Flow transitions in collisions between vortex-rings and density interfaces |
| title_short | Flow transitions in collisions between vortex-rings and density interfaces |
| title_sort | flow transitions in collisions between vortex rings and density interfaces |
| topic | Engineering::Mechanical engineering Vortex-Ring Collision |
| url | https://hdl.handle.net/10356/160898 |
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