Tubercle Effect
The Tubercle Effect is a recently discovered phenomenon where tubercles or large 'bumps' on the leading edge of an airfoil can improve its aerodynamics. The effect was discovered and analyzed by Dr. Frank E. Fish in the late 2000s. The Tubercle Effect works by channeling flow over the airfoil into more narrow streams, creating higher velocities. Another side effect of this channels is the reduction of flow moving over the wing-tip and resulting in less parasitic drag due to wingtip vortices. Dr. Fish first discovered this effect when looking at the fins of humpback whales. These whales are the only known organisms to take advantage of the Tubercle Effect. It is believed that this effect allows them to be much more maneuverable in the water, allowing for easier capture of prey.
See also
References
P. Watts and F. E. Fish, The Influence of Passive, Leading Edge Tubercles on Wing Performance