Meeting Abstract

P1.117  Tuesday, Jan. 4  The role of wing geometry on batoid gait selection BLAIR, J.T.*; IWASAKI, T.; Univ. of Virginia; Univ. of Virginia jtb8s@virginia.edu

A dynamic model of batoid swimming is developed and analyzed for three specific species: the Atlantic, Butterfly, and Cownose rays. These species are chosen for their close biological relationship and variety of observed swimming gaits, from undulation (passing waves down the fin) to oscillation (bird-like flapping). Each species is modeled using biological parameters, such as wing size and shape, approximate fluid forces, observed frequency of wing oscillation, and swim velocity. Optimal swimming gaits with respect to various criteria, including energy efficiency, muscle tension, and wing curvature, are calculated for each case and compared. A general trend is observed where undulatory gaits result for lower aspect ratio, elliptic wing shapes and oscillatory gaits result for higher aspect ratio, triangular wing shapes, which agrees with biology. Gait transitions are also observed as oscillation frequency is changed, from symmetric gaits with pitching of the body at higher frequencies to anti-symmetric gaits with rolling of the body at lower frequencies, both of which are observed in batoid swimming.