Determining self-propelled swimming speeds of isolated fin models for a range of kinematic and planform geometry parameters

When moving through an aquatic environment, many swimming animals use an oscillating caudal fin or fluke to generate forward propulsion. Among the various species of swimming animals, propulsive appendages may display significant diversity in geometric factors like planform shape, leading edge shape, and trailing edge shape. The current work builds on prior experimental work that investigated the swimming speeds of bio-inspired pitching and heaving propulsors in a recirculating water tunnel. Rather than focusing on performance measurements captured for a fixed velocity freestream flow, the current work studies performance using experiments to determine self-propelled swimming speeds for combined pitching and heaving motions. Trailing edge and leading edge shapes, as well as kinematic parameters, are varied for a series of bio-inspired panels with a nominally trapezoidal planform. Thirteen unique panel geometries were actuated through multiple motion profiles until the resultant self-propelled swimming speed was determined. Panel geometries were systematically changed in a manner that allows for investigations into specific geometric factors and their influence on non-dimensional swimming speeds. Results are discussed in the context of changes to planform shape, area, aspect ratio, geometric centroid, and kinematics. The current work has implications on the design of bio-inspired vehicles during conditions of constant velocity swimming.