Numerical investigation of small fish accelerating impulsively to terminal speed
The present paper discusses acceleration in the swimming of a small three-dimensional fish with two motions, carangiform and anguilliform. Flow fields generated by fish deformations are investigated numerically by the constrained interpolation profile method in combination with an immersed boundary...
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| Format: | Article |
| Language: | English |
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The Japan Society of Mechanical Engineers
2017-05-01
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| Series: | Journal of Fluid Science and Technology |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/jfst/12/1/12_2017jfst0009/_pdf/-char/en |
| _version_ | 1819282240563052544 |
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| author | Yoichi OGATA Takayuki AZAMA Yuji MORIYAMA |
| author_facet | Yoichi OGATA Takayuki AZAMA Yuji MORIYAMA |
| author_sort | Yoichi OGATA |
| collection | DOAJ |
| description | The present paper discusses acceleration in the swimming of a small three-dimensional fish with two motions, carangiform and anguilliform. Flow fields generated by fish deformations are investigated numerically by the constrained interpolation profile method in combination with an immersed boundary method. The three-dimensional vortical structure visualized using a second invariant and the pressure field around the fish body show that a fish with anguilliform motion accelerates more rapidly than one with carangiform motion because of a larger thrust due to the strong transverse vortex in the wake of the fish and a large pressure variation around the fish body. It is also found that the time variations of inline swimming speed of a small fish and the fluid force acting on it can be estimated using a free-fall model, and the fluid force can be expressed by a linear function of the fish speed. This function consists of a thrust part that is independent of fish speed and a viscous drag part that is proportional to fish speed. Thus, time histories of swimming speed, swimming distance, and fluid force can be predicted by simple functions from rest to terminal speed. |
| first_indexed | 2024-12-24T01:12:27Z |
| format | Article |
| id | doaj.art-cc2e578a07d7444885038625b196d95e |
| institution | Directory Open Access Journal |
| issn | 1880-5558 |
| language | English |
| last_indexed | 2024-12-24T01:12:27Z |
| publishDate | 2017-05-01 |
| publisher | The Japan Society of Mechanical Engineers |
| record_format | Article |
| series | Journal of Fluid Science and Technology |
| spelling | doaj.art-cc2e578a07d7444885038625b196d95e2022-12-21T17:22:51ZengThe Japan Society of Mechanical EngineersJournal of Fluid Science and Technology1880-55582017-05-01121JFST0009JFST000910.1299/jfst.2017jfst0009jfstNumerical investigation of small fish accelerating impulsively to terminal speedYoichi OGATA0Takayuki AZAMA1Yuji MORIYAMA2Department of Mechanical System Engineering, Hiroshima UniversityDepartment of Mechanical System Engineering, Hiroshima UniversityDepartment of Mechanical System Engineering, Hiroshima UniversityThe present paper discusses acceleration in the swimming of a small three-dimensional fish with two motions, carangiform and anguilliform. Flow fields generated by fish deformations are investigated numerically by the constrained interpolation profile method in combination with an immersed boundary method. The three-dimensional vortical structure visualized using a second invariant and the pressure field around the fish body show that a fish with anguilliform motion accelerates more rapidly than one with carangiform motion because of a larger thrust due to the strong transverse vortex in the wake of the fish and a large pressure variation around the fish body. It is also found that the time variations of inline swimming speed of a small fish and the fluid force acting on it can be estimated using a free-fall model, and the fluid force can be expressed by a linear function of the fish speed. This function consists of a thrust part that is independent of fish speed and a viscous drag part that is proportional to fish speed. Thus, time histories of swimming speed, swimming distance, and fluid force can be predicted by simple functions from rest to terminal speed.https://www.jstage.jst.go.jp/article/jfst/12/1/12_2017jfst0009/_pdf/-char/ensmall fishswimmingaccelerationfluid forcefluid-structure interactioncip methodnumerical simulationvortical structure |
| spellingShingle | Yoichi OGATA Takayuki AZAMA Yuji MORIYAMA Numerical investigation of small fish accelerating impulsively to terminal speed Journal of Fluid Science and Technology small fish swimming acceleration fluid force fluid-structure interaction cip method numerical simulation vortical structure |
| title | Numerical investigation of small fish accelerating impulsively to terminal speed |
| title_full | Numerical investigation of small fish accelerating impulsively to terminal speed |
| title_fullStr | Numerical investigation of small fish accelerating impulsively to terminal speed |
| title_full_unstemmed | Numerical investigation of small fish accelerating impulsively to terminal speed |
| title_short | Numerical investigation of small fish accelerating impulsively to terminal speed |
| title_sort | numerical investigation of small fish accelerating impulsively to terminal speed |
| topic | small fish swimming acceleration fluid force fluid-structure interaction cip method numerical simulation vortical structure |
| url | https://www.jstage.jst.go.jp/article/jfst/12/1/12_2017jfst0009/_pdf/-char/en |
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