Meeting Abstract

68.4  Thursday, Jan. 6  Analytical model to describe pectoral fin kinematics of the Manta birostris: implications for bio-inspired design MOORED, K. W.*; QUINN, D. B.; FISH, F. E.; HAJ-HARIRI, H.; BART-SMITH, H.; Princeton University; Princeton University; West Chester University; University of Virginia; University of Virginia kwm3x@virginia.edu

Manta rays are large pelagic fish that are dorsoventrally flattened with enlarged pectoral fins. These rays oscillate their pectoral fins in complex three-dimensional motions in order to produce thrust and are thought to exhibit efficient locomotion due to their perceived effortless swimming. However, no estimates of their swimming performance have been calculated nor have the kinematics of their pectoral fins been directly measured due to the lack of visibly trackable features and the inability to mark such rare animals. Thus an analytical model to estimate the three-dimensional pectoral fin kinematics of the manta ray is developed. It captures the dominant components of ray locomotion: curved spanwise deformation coupled with a chordwise traveling wave. Key features of locomotion are measured from photographic images and are used to determine 4 fitting parameters. The model is constrained to have near zero strain in the span direction during flapping while matching the spanwise curvature, amplitude and nondimensional wavenumbers exhibited by manta rays. The model is extended to quantify the kinematics of the entire batoid family, Batoidea, with examples presented of two other species, the Atlantic stingray, Dasyatis sabina, and the cownose ray, Rhinoptera bonasus. The kinematic model is coupled with a vortex panel method to estimate four rectilinear swimming performance metrics: thrust production, propulsive efficiency, swimming speed and swimming economy. The performance metrics for the Atlantic stingray and the manta ray are compared. Lastly, the kinematic model supplies a target deformation field for the design of an artificial pectoral fin. The example of a tensegrity-based fin is presented.