65.4 Thursday, Jan. 6 Understanding Batoid Propulsion Through Artificial Structures KEMP, T*; BART-SMITH, H; MOORED, K; University of Virginia; University of Virginia; Princeton University firstname.lastname@example.org
The manta ray (Manta birostris) is known for its swimming maneuverability and it is thought that these animals have a high long range cruising efficiency; both of these qualities are achieved with combined propulsive/control surface pectoral fins. These qualities make the biological specimen an interesting model to emulate for an autonomous underwater vehicle. However, the mechanics of its swimming style are still not understood. Due to the challenges associated with obtaining quantitative data on the swimming performance of these animals and relating it to observed fin kinematics, the current study aims to understand batoid swimming mechanics by means of testing artificial (robotic) pectoral fins in a controlled environment. Active tensegrity structures are embedded in an elastomer skin to create an artificial pectoral fin that approximates the motions of a biological fin: high amplitude, curved span-wise flapping combined with a chord-wise traveling wave. The combination of these two motions can be varied to represent a range of species across the undulatory/oscillatory continuum within Batoidea. The bulk performance metrics (thrust, swimming velocity, propulsive efficiency, and swimming economy) of this fin are measured in a flow tank over a range of flapping parameters. These measurements point to areas of peak performance where we can further investigate the hydrodynamics of unsteady flow by doing flow visualization, thereby finding connections between vortex shedding and observed performance. Moreover, this study sheds light on the exploitation of unsteady flow in batoid swimming, clearing way for the design of a batoid-inspired vehicle.