Computational modelling and analysis of the hydrodynamics of a highly deformable fish pectoral fin
Numerical simulations are used to investigate the flow associated with a bluegill sunfish (Lepomis macrochirus) pectoral fin during steady forward motion. The simulations are intended to match the experiments of Lauder et al. (Bioinsp. Biomim., vol. 1, 2006, p. S25), and the results obtained from th...
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Published in | Journal of fluid mechanics Vol. 645; pp. 345 - 373 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Cambridge, UK
Cambridge University Press
25.02.2010
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Subjects | |
Online Access | Get full text |
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Summary: | Numerical simulations are used to investigate the flow associated with a bluegill sunfish (Lepomis macrochirus) pectoral fin during steady forward motion. The simulations are intended to match the experiments of Lauder et al. (Bioinsp. Biomim., vol. 1, 2006, p. S25), and the results obtained from the simulations complement the experimental analysis. The focus of the current paper is on the quantitative characterization of the propulsive performance of the pectoral fin, which undergoes significant deformation during its stroke. This includes a detailed analysis of the thrust production mechanisms as well as their connection to the vortex dynamics and other flow features. The simulations indicate that the fish fin produces high propulsive performance by employing a complex fin gait driven by active and passive fin deformation. By connecting the vortex dynamics and fin kinematics with the surface distribution of the force on the fin, it is found that during abduction, the fin moves such that the tip of the fin undergoes a complex, three-dimensional flapping motion that produces a strong and long-lasting, attached tip vortex. This tip vortex is associated with most of the thrust production during the abduction phase of the stroke. During the adduction phase, the fin motion is similar to a ‘paddling’ stroke. Comparisons are made with rigid flapping foils to provide insights into the remarkable performance of the fish fin and to interpret the force production from the viewpoint of functional morphology. |
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Bibliography: | ark:/67375/6GQ-JD93XT3G-4 PII:S0022112009992941 ArticleID:99294 Present address: 126 Russ Center, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435, USA. istex:6FA3B20A08141F4386F5630B44583972781E7849 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 ObjectType-Article-2 ObjectType-Feature-1 |
ISSN: | 0022-1120 1469-7645 |
DOI: | 10.1017/S0022112009992941 |