Hydrodynamic forces on a side-by-side ellipse pair with and without relative motion
Motivated by flow interactions in schooling biological swimmers as well as in unmanned underwater vehicle fleets, we investigate the flow past two identical 6 : 1 ellipses using two-dimensional simulations at Reynolds numbers of (103). When both ellipses move at the same velocity, overall drag red...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
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Cambridge University Press
2024
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| Online Access: | https://hdl.handle.net/1721.1/157676 |
| _version_ | 1824457926095405056 |
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| author | Rhodes, Preston van Rees, Wim M. |
| author2 | Massachusetts Institute of Technology. Department of Mechanical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Mechanical Engineering Rhodes, Preston van Rees, Wim M. |
| author_sort | Rhodes, Preston |
| collection | MIT |
| description | Motivated by flow interactions in schooling biological swimmers as well as in unmanned underwater vehicle fleets, we investigate the flow past two identical 6 : 1 ellipses using two-dimensional simulations at Reynolds numbers of (103). When both ellipses move at the same velocity, overall drag reductions of 10 %–20 % can be achieved in staggered formations, with the strongest drag reductions occurring at the smallest lateral distances. In side-by-side configurations, the drag on both bodies increases by 10 %–20 %. Lift coefficients are repulsive and up to four times larger than the total drag coefficients. During overtaking manoeuvres, increasing the relative speed of the overtaking ellipse predominantly affects the forces on the overtaken ellipse. The mean drag force on the overtaken ellipse increases with increasing speed difference. Mean lift forces during the overtaking manoeuvre are repulsive for both bodies; as the speed difference increases, the repulsive force increases on the overtaken body and decreases on the overtaking body. Overall, these results highlight that the lateral forces in hydrodynamic interactions between bodies in formation dominate the hydrodynamic interactions. Further, the results indicate that future work is needed to investigate how viscous and three-dimensional effects change the lateral forces between side-by-side submerged bodies. |
| first_indexed | 2025-02-19T04:17:45Z |
| format | Article |
| id | mit-1721.1/157676 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2025-02-19T04:17:45Z |
| publishDate | 2024 |
| publisher | Cambridge University Press |
| record_format | dspace |
| spelling | mit-1721.1/1576762024-12-23T05:56:53Z Hydrodynamic forces on a side-by-side ellipse pair with and without relative motion Rhodes, Preston van Rees, Wim M. Massachusetts Institute of Technology. Department of Mechanical Engineering Motivated by flow interactions in schooling biological swimmers as well as in unmanned underwater vehicle fleets, we investigate the flow past two identical 6 : 1 ellipses using two-dimensional simulations at Reynolds numbers of (103). When both ellipses move at the same velocity, overall drag reductions of 10 %–20 % can be achieved in staggered formations, with the strongest drag reductions occurring at the smallest lateral distances. In side-by-side configurations, the drag on both bodies increases by 10 %–20 %. Lift coefficients are repulsive and up to four times larger than the total drag coefficients. During overtaking manoeuvres, increasing the relative speed of the overtaking ellipse predominantly affects the forces on the overtaken ellipse. The mean drag force on the overtaken ellipse increases with increasing speed difference. Mean lift forces during the overtaking manoeuvre are repulsive for both bodies; as the speed difference increases, the repulsive force increases on the overtaken body and decreases on the overtaking body. Overall, these results highlight that the lateral forces in hydrodynamic interactions between bodies in formation dominate the hydrodynamic interactions. Further, the results indicate that future work is needed to investigate how viscous and three-dimensional effects change the lateral forces between side-by-side submerged bodies. 2024-11-26T14:01:19Z 2024-11-26T14:01:19Z 2024-11-13 Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/157676 Rhodes P, van Rees WM. Hydrodynamic forces on a side-by-side ellipse pair with and without relative motion. Flow. 2024;4:E27. en_US https://doi.org/10.1017/flo.2024.21 Flow Creative Commons Attribution An error occurred on the license name. https://creativecommons.org/licenses/by/4.0/ application/pdf Cambridge University Press Cambridge University Press |
| spellingShingle | Rhodes, Preston van Rees, Wim M. Hydrodynamic forces on a side-by-side ellipse pair with and without relative motion |
| title | Hydrodynamic forces on a side-by-side ellipse pair with and without relative motion |
| title_full | Hydrodynamic forces on a side-by-side ellipse pair with and without relative motion |
| title_fullStr | Hydrodynamic forces on a side-by-side ellipse pair with and without relative motion |
| title_full_unstemmed | Hydrodynamic forces on a side-by-side ellipse pair with and without relative motion |
| title_short | Hydrodynamic forces on a side-by-side ellipse pair with and without relative motion |
| title_sort | hydrodynamic forces on a side by side ellipse pair with and without relative motion |
| url | https://hdl.handle.net/1721.1/157676 |
| work_keys_str_mv | AT rhodespreston hydrodynamicforcesonasidebysideellipsepairwithandwithoutrelativemotion AT vanreeswimm hydrodynamicforcesonasidebysideellipsepairwithandwithoutrelativemotion |