67th Annual Meeting of the APS Division of Fluid Dynamics (November 23, 2014 — November 25, 2014)

P0057: Steering and Maneuvering in Jellyfish Bells

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Authors

• Alexander Hoover, University of North Carolina at Chapel Hill
• Laura Miller, University of North Carolina at Chapel Hill
• Boyce Griffith, University of North Carolina at Chapel Hill

DOI: https://doi.org/10.1103/APS.DFD.2014.GFM.P0057

Using a immersed boundary simulation of an elastic jellyfish bell, we model jellyfish propulsion by applying an active tension to the lower half of bell that pushes fluid out of the bell and transfers momentum from the bell to the surrounding fluid environment. The tension is then released and the bell is allowed to passively expand to its original form. A vortex ring is ejected from the bell during the expansion and travels in the opposite direction of the bell. Since the bell is initially at rest, the downward velocity of the initial vortex ring is slower than the second vortex ring and so the second vortex leapfrogs the initial vortex in the wake. This effect disappears as the bell reaches its steady state swimming velocity.