The Tubercles on Humpback Whales' Flippers: Application of Bio-Inspired Technology

• Main Authors: Fish, Frank E, Weber, Paul W, Murray, Mark M, Howle, Laurens S
• Other Authors: NAVAL ACADEMY ANNAPOLIS MD DEPT OF MECHANICAL ENGINEERING
• Format: Text
• Language: English
• Published: 2011
• Subjects: Biological Oceanography; Fluid Mechanics; *FLIPPERS; *HYDRODYNAMICS; BIOMECHANICS; LEADING EDGES; REPRINTS; WHALES; PASSIVE FLOW CONTROL DEVICES; HUMPBACK WHALE(MEGAPTERA NOVAEANGLIAE); TUBERCLES; Arlington; baleen whales; Humpback Whale; Megaptera novaeangliae
• Online Access: http://www.dtic.mil/docs/citations/ADA555120; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA555120

The humpback whale (Megaptera novaeangliae) is exceptional among the large baleen whales in its ability to undertake aquabatic maneuvers to catch prey. Humpback whales utilize extremely mobile, wing-like flippers for banking and turning. Large rounded tubercles along the leading edge of the flipper are morphological structures that are unique in nature. The tubercles on the leading edge act as passive-flow control devices that improve performance and maneuverability of the flipper. Experimental analysis of finite wing models has demonstrated that the presence of tubercles produces a delay in the angle of attack until stall, thereby increasing maximum lift and decreasing drag. Possible fluid-dynamic mechanisms for improved performance include delay of stall through generation of a vortex and modification of the boundary layer, and increase in effective span by reduction of both spanwise flow and strength of the tip vortex. The tubercles provide a bio-inspired design that has commercial viability for wing-like structures. Control of passive flow has the advantages of eliminating complex, costly, high-maintenance, and heavy control mechanisms, while improving performance for lifting bodies in air and water. The tubercles on the leading edge can be applied to the design of watercraft, aircraft, ventilation fans, and windmills. Published in Integrative and Comparative Biology, v51 n1 p203-213, May 2011. From the symposium Bioinspiration: Applying Mechanical Design to Experimental Biology presented at the annual meeting of the Society for Integrative and Comparative Biology, January 3 7, 2011, at Salt Lake City, Utah. Prepared in collaboration with Department of Biology, West Chester University, West Chester, PA, Applied Research Associates Inc., Arlington, VA and Mechanical Engineering and Material Science Department and Center for Nonlinear and Complex Systems, Duke University, Durham, NC.