Content on this page requires a newer version of Adobe Flash Player.

Get Adobe Flash player

Trevor Kemp pusues his graduate degree while leading this area of study on grounds at the University of Virginia.

Pectoral Fin Hydrodynamics

The majority of the motion seen in batoid pectoral fins can be described as a superposition of a large amplitude oscillatory bending in the span-wise direction, with an undulatory wave traveling down the chord-wise direction. To study the hydrodynamics of batoid swimming, robotic fins which exhibit these two major components have been developed.

Biological ray fins are a composite structure with both active (force generating) and passive (compliant) components. Taking inspiration from biology, the current robotic fins being developed and studied have actuated active tensegrity leading edges and passively compliant trailing edges. The motion of the leading edge is prescribed to match biological amplitudes, while the remainder of the fin passively deforms under the influence of hydrodynamic loads, producing an undulatory component to the motion.

Bulk performance metrics of the fins are measured, such as thrust, swimming velocity, power consumed, and swimming efficiency. These measures can be used to quantify the relationship between kinematic parameters and the resulting performance. In addition, the complex wake structures produced by the fins are studied through a variety of techniques, including dye-flow visualization, shadow graphs, and particle image velocimetry.