69th Annual Meeting of the APS Division of Fluid Dynamics (November 20, 2016 — November 22, 2016)

V0111: Swimming Upstream: Computational Hydrodynamics of Trout Locomotion

Authors

• Yan Ren, University of Virginia
• Geng Liu, University of Virginia
• Pan Han, University of Virginia
• Haibo Dong, University of Virginia
• Valentina Di Santo, Harvard University
• George Lauder, Harvard University

DOI: https://doi.org/10.1103/APS.DFD.2016.GFM.V0111

Trout is thought to be one of the fresh water fish that can swim at a high propulsive efficiency. The unsteady vortex dynamics is key to understand the hydrodynamics of trout swimming. Here we present an integrated approach combining high-speed photogrammetry, surface reconstruction, and direct numerical simulations to study the three-dimensional vortex dynamics of a trout in both steady swimming and burst-coast. The trout body model is comprised of a trunk, a dorsal fin, an anal fin, and a caudal fin. The undulatory motion of the model is reconstructed based on high-speed videos from three orthogonal views. The vortex dynamics of both steady swimming and burst-coast is visualized by three-dimensional flow structures. The vortex formation in the near wake shows strong vortical interactions between the fore fins (dorsal and anal) and the caudal fin in both swimming modes. However, the caudal fin generates much stronger vortex rings during the burst stage than that of the steady swimming. (This work was supported by the ONR MURI N00014-14-1-0533 and NSF CBET-1313217)