Coherent structures in the breakdown bubble of a vortex flow
Helical structures downstream of the breakdown-bubble of the Grabowski vortex profile at Reynolds numbers Re< or = 500 have been extensively studied through stability analysis in the literature. However, the low-frequency coherent structures inside the bubble, which have been observed in experime...
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| Format: | Article |
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American Institute of Aeronautics and Astronautics
2018
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| Online Access: | https://eprints.nottingham.ac.uk/49569/ |
| _version_ | 1848798026572759040 |
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| author | Paterson, Oliver Wang, Bofu Mao, Xuerui |
| author_facet | Paterson, Oliver Wang, Bofu Mao, Xuerui |
| author_sort | Paterson, Oliver |
| building | Nottingham Research Data Repository |
| collection | Online Access |
| description | Helical structures downstream of the breakdown-bubble of the Grabowski vortex profile at Reynolds numbers Re< or = 500 have been extensively studied through stability analysis in the literature. However, the low-frequency coherent structures inside the bubble, which have been observed in experiments, were not predicted by the stability approach. In the present work, asymptotic stabilities of the Grabowski vortex flow at Re < or = 1000 are carried out to compare against previous works, and then the linear optimal inflow perturbation and the corresponding outcome are studied to unveil the dynamics inside the bubble. It is found that low frequency inflow perturbations penetrate the bubble and are amplified to coherent structures, while high frequency perturbations are convected around the border of the bubble. These linearised results agree well with previous experimental observations and are validated by direct numerical simulations. |
| first_indexed | 2025-11-14T20:13:14Z |
| format | Article |
| id | nottingham-49569 |
| institution | University of Nottingham Malaysia Campus |
| institution_category | Local University |
| last_indexed | 2025-11-14T20:13:14Z |
| publishDate | 2018 |
| publisher | American Institute of Aeronautics and Astronautics |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | nottingham-495692020-05-04T19:38:10Z https://eprints.nottingham.ac.uk/49569/ Coherent structures in the breakdown bubble of a vortex flow Paterson, Oliver Wang, Bofu Mao, Xuerui Helical structures downstream of the breakdown-bubble of the Grabowski vortex profile at Reynolds numbers Re< or = 500 have been extensively studied through stability analysis in the literature. However, the low-frequency coherent structures inside the bubble, which have been observed in experiments, were not predicted by the stability approach. In the present work, asymptotic stabilities of the Grabowski vortex flow at Re < or = 1000 are carried out to compare against previous works, and then the linear optimal inflow perturbation and the corresponding outcome are studied to unveil the dynamics inside the bubble. It is found that low frequency inflow perturbations penetrate the bubble and are amplified to coherent structures, while high frequency perturbations are convected around the border of the bubble. These linearised results agree well with previous experimental observations and are validated by direct numerical simulations. American Institute of Aeronautics and Astronautics 2018-05-30 Article PeerReviewed Paterson, Oliver, Wang, Bofu and Mao, Xuerui (2018) Coherent structures in the breakdown bubble of a vortex flow. AIAA Journal, 56 (5). 1812 -1817. ISSN 1533-385X https://arc.aiaa.org/doi/10.2514/1.J055329 doi:10.2514/1.J055329 doi:10.2514/1.J055329 |
| spellingShingle | Paterson, Oliver Wang, Bofu Mao, Xuerui Coherent structures in the breakdown bubble of a vortex flow |
| title | Coherent structures in the breakdown bubble of a vortex flow |
| title_full | Coherent structures in the breakdown bubble of a vortex flow |
| title_fullStr | Coherent structures in the breakdown bubble of a vortex flow |
| title_full_unstemmed | Coherent structures in the breakdown bubble of a vortex flow |
| title_short | Coherent structures in the breakdown bubble of a vortex flow |
| title_sort | coherent structures in the breakdown bubble of a vortex flow |
| url | https://eprints.nottingham.ac.uk/49569/ https://eprints.nottingham.ac.uk/49569/ https://eprints.nottingham.ac.uk/49569/ |