The hydraulic bump: The surface signature of a plunging jet
When a falling jet of fluid strikes a horizontal fluid layer, a hydraulic jump arises downstream of the point of impact, provided a critical flow rate is exceeded. We here examine a phenomenon that arises below this jump threshold, a circular deflection of relatively small amplitude on the free surf...
| Main Authors: | , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
American Institute of Physics (AIP)
2015
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| Online Access: | http://hdl.handle.net/1721.1/92860 https://orcid.org/0000-0002-7936-7256 |
| _version_ | 1826209666465529856 |
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| author | Labousse, M. Bush, John W. M. |
| author2 | Massachusetts Institute of Technology. Department of Mathematics |
| author_facet | Massachusetts Institute of Technology. Department of Mathematics Labousse, M. Bush, John W. M. |
| author_sort | Labousse, M. |
| collection | MIT |
| description | When a falling jet of fluid strikes a horizontal fluid layer, a hydraulic jump arises downstream of the point of impact, provided a critical flow rate is exceeded. We here examine a phenomenon that arises below this jump threshold, a circular deflection of relatively small amplitude on the free surface that we call the hydraulic bump. The form of the circular bump can be simply understood in terms of the underlying vortex structure and its height simply deduced with Bernoulli arguments. As the incoming flux increases, a breaking of axial symmetry leads to polygonal hydraulic bumps. The relation between this polygonal instability and that arising in the hydraulic jump is discussed. The coexistence of hydraulic jumps and bumps can give rise to striking nested structures with polygonal jumps bound within polygonal bumps. The absence of a pronounced surface signature on the hydraulic bump indicates the dominant influence of the subsurface vorticity on its instability. |
| first_indexed | 2024-09-23T14:26:28Z |
| format | Article |
| id | mit-1721.1/92860 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T14:26:28Z |
| publishDate | 2015 |
| publisher | American Institute of Physics (AIP) |
| record_format | dspace |
| spelling | mit-1721.1/928602022-10-01T21:19:27Z The hydraulic bump: The surface signature of a plunging jet Labousse, M. Bush, John W. M. Massachusetts Institute of Technology. Department of Mathematics Bush, John W. M. When a falling jet of fluid strikes a horizontal fluid layer, a hydraulic jump arises downstream of the point of impact, provided a critical flow rate is exceeded. We here examine a phenomenon that arises below this jump threshold, a circular deflection of relatively small amplitude on the free surface that we call the hydraulic bump. The form of the circular bump can be simply understood in terms of the underlying vortex structure and its height simply deduced with Bernoulli arguments. As the incoming flux increases, a breaking of axial symmetry leads to polygonal hydraulic bumps. The relation between this polygonal instability and that arising in the hydraulic jump is discussed. The coexistence of hydraulic jumps and bumps can give rise to striking nested structures with polygonal jumps bound within polygonal bumps. The absence of a pronounced surface signature on the hydraulic bump indicates the dominant influence of the subsurface vorticity on its instability. National Science Foundation (U.S.) (Grant DMS-0907955) 2015-01-14T17:10:08Z 2015-01-14T17:10:08Z 2013-09 2013-05 Article http://purl.org/eprint/type/JournalArticle 10706631 1089-7666 http://hdl.handle.net/1721.1/92860 Labousse, M., and J. W. M. Bush. “The Hydraulic Bump: The Surface Signature of a Plunging Jet.” Physics of Fluids 25, no. 9 (2013): 094104. https://orcid.org/0000-0002-7936-7256 en_US http://dx.doi.org/10.1063/1.4821360 Physics of Fluids Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Institute of Physics (AIP) MIT web domain |
| spellingShingle | Labousse, M. Bush, John W. M. The hydraulic bump: The surface signature of a plunging jet |
| title | The hydraulic bump: The surface signature of a plunging jet |
| title_full | The hydraulic bump: The surface signature of a plunging jet |
| title_fullStr | The hydraulic bump: The surface signature of a plunging jet |
| title_full_unstemmed | The hydraulic bump: The surface signature of a plunging jet |
| title_short | The hydraulic bump: The surface signature of a plunging jet |
| title_sort | hydraulic bump the surface signature of a plunging jet |
| url | http://hdl.handle.net/1721.1/92860 https://orcid.org/0000-0002-7936-7256 |
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