Numerical Simulation of a Three-Dimensional Fish-like Body Swimming with Finlets

Wang, Shizhao; Zhang, Xing; He, Guowei

doi:10.4208/cicp.090510.150511s

Cited by 16 publications

(14 citation statements)

References 23 publications

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“…Similar elongated dorsal/anal fins were studied in crevalle jack (Caranx hippos) swimming [16]. Among these results, finlets/fins were found to operate in the local flow that is converging to the posterior body, mainly induced by the posteriorly narrowed body of the fishes [14,16]. Enhanced mean thrust and propulsive efficiency attributed to the simplified finlets were found in a tuna-like model [13,15].…”

Section: Introductionmentioning

confidence: 61%

Tuna locomotion: a computational hydrodynamic analysis of finlet function

Wang

Wainwright

Lindengren

et al. 2020

J. R. Soc. Interface.

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Finlets are a series of small non-retractable fins common to scombrid fishes (mackerels, bonitos and tunas), which are known for their high swimming speed. It is hypothesized that these small fins could potentially affect propulsive performance. Here, we combine experimental and computational approaches to investigate the hydrodynamics of finlets in yellowfin tuna ( Thunnus albacares ) during steady swimming. High-speed videos were obtained to provide kinematic data on the in vivo motion of finlets. High-fidelity simulations were then carried out to examine the hydrodynamic performance and vortex dynamics of a biologically realistic multiple-finlet model with reconstructed kinematics. It was found that finlets undergo both heaving and pitching motion and are delayed in phase from anterior to posterior along the body. Simulation results show that finlets were drag producing and did not produce thrust. The interactions among finlets helped reduce total finlet drag by 21.5%. Pitching motions of finlets helped reduce the power consumed by finlets during swimming by 20.8% compared with non-pitching finlets. Moreover, the pitching finlets created constructive forces to facilitate posterior body flapping. Wake dynamics analysis revealed a unique vortex tube matrix structure and cross-flow streams redirected by the pitching finlets, which supports their hydrodynamic function in scombrid fishes. Limitations on modelling and the generality of results are also discussed.

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Section: Introductionmentioning

confidence: 61%

Tuna locomotion: a computational hydrodynamic analysis of finlet function

Wang

Wainwright

Lindengren

et al. 2020

J. R. Soc. Interface.

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show abstract

“…To this end, the actual Reynolds number is reduced to 1200 for meeting the requirement of the mesh resolution and computation cost by direct numerical simulation of swimming objects. [8][9][10][11][12] This is equivalent to either a smaller size body performing a similar motion or using the same body performing a slower motion. 12 The nominal grid size employed in the simulations is 264 × 178 × 264, which gives approximately 12.4 million grid points in total.…”

Section: ×mentioning

confidence: 99%

Thrust producing mechanisms in ray-inspired underwater vehicle propulsion

Ren

Zhu

et al. 2015

Theoretical and Applied Mechanics Letters

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“…The mechanism research plays an important role and will boost the development of the principle prototype. To reveal the mechanism of high-efficiency propulsion, scholars at home and abroad have devoted considerable effort with different research methods [5][6][7]. However, both the prototype-based experimental results and the numerical results achieved are far from the expected performance.…”

Section: Introductionmentioning

confidence: 99%

Study on the Hydrodynamic Performance of Typical Underwater Bionic Foils with Spanwise Flexibility

2017

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Bionic foils are usually similar in shape to the locomotive organs of animals living in fluid media, which is helpful in the analysis of the motion mode and hydrodynamic mechanisms of biological prototypes. With the design of underwater vehicles as the research background, bionic foils are adopted as research objects in this paper. A geometric model and a motion model are established depending on the biological prototype. In the model, two typical bionic foils-a NACA foil and a crescent-shaped foil-are chosen as research objects. Simulations of the bionic foils are performed using a numerical method based on computational fluid dynamics software. The hydrodynamic forces acting on the foils and flow field characteristics behind the foils are used to analyze the propulsion performance and hydrodynamic mechanism. Furthermore, a spanwise flexibility model is introduced into the motion model. Next, the hydrodynamic mechanism is further analyzed on the basis of hydrodynamic forces and flow field characteristics with different spanwise flexibility parameters. Finally, an experimental verification platform is designed and built to verify the reliability of the numerical results. Agreement between the experimental and numerical results indicates that the numerical results are reliable and that the analysis of the paper is reasonable.

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Numerical Simulation of a Three-Dimensional Fish-like Body Swimming with Finlets

Cited by 16 publications

References 23 publications

Tuna locomotion: a computational hydrodynamic analysis of finlet function

Tuna locomotion: a computational hydrodynamic analysis of finlet function

Thrust producing mechanisms in ray-inspired underwater vehicle propulsion

Study on the Hydrodynamic Performance of Typical Underwater Bionic Foils with Spanwise Flexibility

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