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The leading-edge tubercles of humpback whale flippers have been shown to enhance hydrodynamic performance
by increasing lift and decreasing drag poststall. To explore this effect, computational simulations of two models based
on an idealized humpback whale flipper were conducted, one with a smooth leading edge and one with simulated
leading-edge tubercles. Two different commercial computational fluid dynamics packages were used, STAR-CCM+
and SolidWorks Flow Simulation, and the results were compared with experiment. Numeric lift predictions in the
nonstall region were reasonably accurate (maximum error 6.6% between both codes), while lift predictions in the
poststall region were problematic. Numeric drag predictions in the early nonstall region were within experimental
error for STAR-CCM+ using the Spalart–Allmaras turbulence model, while both codes exhibited drag prediction
error in the stall region. Flow visualizations showed that the smooth flipper exhibited trailing-edge stall, while the
simulated tubercle flipper stalled in the troughs, behind the leading notches, first. At high angles of attack, the
simulated tubercle flipper still possessed significant regions of attached flow, which contributes to its ability to
maintain increased lift poststall.