Cavity dynamics in water entry at low Froude numbers
The dynamics of the air cavity created by vertical water entry of a three-dimensional body is investigated theoretically, computationally and experimentally. The study is focused in the range of relatively low Froude numbers, Fr ≡ V(gD)−1/2 ≤ O(10) (where V is the dropping velocity of the body, D it...
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| Format: | Article |
| Language: | en_US |
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Cambridge University Press
2013
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| Online Access: | http://hdl.handle.net/1721.1/81309 https://orcid.org/0000-0003-1273-9964 |
| _version_ | 1826212806515490816 |
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| author | Yan, Hongmei Liu, Yuming Kominiarczuk, Jakub Yue, Dick K. P. |
| author2 | Massachusetts Institute of Technology. Department of Mechanical Engineering |
| author_facet | Massachusetts Institute of Technology. Department of Mechanical Engineering Yan, Hongmei Liu, Yuming Kominiarczuk, Jakub Yue, Dick K. P. |
| author_sort | Yan, Hongmei |
| collection | MIT |
| description | The dynamics of the air cavity created by vertical water entry of a three-dimensional body is investigated theoretically, computationally and experimentally. The study is focused in the range of relatively low Froude numbers, Fr ≡ V(gD)−1/2 ≤ O(10) (where V is the dropping velocity of the body, D its characteristic dimension and g the gravitational acceleration), when the inertia and gravity effects are comparable. To understand the physical processes involved in the evolution of cavity, we conduct laboratory experiments of water entry of freely dropping spheres. A matched asymptotic theory for the description of the cavity dynamics is developed based on the slender-body theory in the context of potential flow. Direct comparisons with experimental data show that the asymptotic theory properly captures the key physical effects involved in the development of the cavity, and in particular gives a reasonable prediction of the maximum size of the cavity and the time of cavity closure. Due to the inherent assumption in the asymptotic theory, it is incapable of accurately predicting the flow details near the free surface and the body, where nonlinear free surface and body boundary effects are important. To complement the asymptotic theory, a fully nonlinear numerical study using an axisymmetric boundary integral equation is performed. The numerically obtained dependencies of the cavity height and closure time on Froude number and body geometry are in excellent agreement with available experiments. |
| first_indexed | 2024-09-23T15:38:12Z |
| format | Article |
| id | mit-1721.1/81309 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T15:38:12Z |
| publishDate | 2013 |
| publisher | Cambridge University Press |
| record_format | dspace |
| spelling | mit-1721.1/813092022-10-02T03:03:21Z Cavity dynamics in water entry at low Froude numbers Yan, Hongmei Liu, Yuming Kominiarczuk, Jakub Yue, Dick K. P. Massachusetts Institute of Technology. Department of Mechanical Engineering Massachusetts Institute of Technology. School of Engineering Yan, Hongmei Liu, Yuming Kominiarczuk, Jakub Yue, Dick K. P. The dynamics of the air cavity created by vertical water entry of a three-dimensional body is investigated theoretically, computationally and experimentally. The study is focused in the range of relatively low Froude numbers, Fr ≡ V(gD)−1/2 ≤ O(10) (where V is the dropping velocity of the body, D its characteristic dimension and g the gravitational acceleration), when the inertia and gravity effects are comparable. To understand the physical processes involved in the evolution of cavity, we conduct laboratory experiments of water entry of freely dropping spheres. A matched asymptotic theory for the description of the cavity dynamics is developed based on the slender-body theory in the context of potential flow. Direct comparisons with experimental data show that the asymptotic theory properly captures the key physical effects involved in the development of the cavity, and in particular gives a reasonable prediction of the maximum size of the cavity and the time of cavity closure. Due to the inherent assumption in the asymptotic theory, it is incapable of accurately predicting the flow details near the free surface and the body, where nonlinear free surface and body boundary effects are important. To complement the asymptotic theory, a fully nonlinear numerical study using an axisymmetric boundary integral equation is performed. The numerically obtained dependencies of the cavity height and closure time on Froude number and body geometry are in excellent agreement with available experiments. United States. Office of Naval Research 2013-10-04T14:27:48Z 2013-10-04T14:27:48Z 2009-11 2009-08 Article http://purl.org/eprint/type/JournalArticle 0022-1120 1469-7645 http://hdl.handle.net/1721.1/81309 YAN, HONGMEI, YUMING LIU, JAKUB KOMINIARCZUK, and DICK K. P. YUE. Cavity Dynamics in Water Entry at Low Froude Numbers. Journal of Fluid Mechanics 641 (December 30, 2009): 441. © Cambridge University Press 2009. https://orcid.org/0000-0003-1273-9964 en_US http://dx.doi.org/10.1017/s0022112009991558 Journal of Fluid Mechanics 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 Cambridge University Press Other University Web Domain |
| spellingShingle | Yan, Hongmei Liu, Yuming Kominiarczuk, Jakub Yue, Dick K. P. Cavity dynamics in water entry at low Froude numbers |
| title | Cavity dynamics in water entry at low Froude numbers |
| title_full | Cavity dynamics in water entry at low Froude numbers |
| title_fullStr | Cavity dynamics in water entry at low Froude numbers |
| title_full_unstemmed | Cavity dynamics in water entry at low Froude numbers |
| title_short | Cavity dynamics in water entry at low Froude numbers |
| title_sort | cavity dynamics in water entry at low froude numbers |
| url | http://hdl.handle.net/1721.1/81309 https://orcid.org/0000-0003-1273-9964 |
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