YachtForums.Com - View Single Post - Aerodynamics & Hydrodynamics from MotherNature

brian eiland · 03-09-2008, 02:16 PM

There's a paragraph at Harvard professor Michael Brenner's pages at
http://www.seas.harvard.edu/brenner/Research%203.html

"We have been interested in understanding the aerodynamic mechanism for this stall-delay. Recent work with Ernst van Nierop and Silas Alben demonstrates the mechanism for the observed increase in stall angle. Although the bumps have been compared to vortex generators, we propose a different mechanism: we demonstrate that the bumps alter the pressure distribution on the wing such that separation of the boundary is delayed behind bumps; this ultimately leads to a gradualonset of stall and higher stall angle. Our mechanism predicts that as the amplitude of the bumps is increased, the lift curve flattens out leading to potentially desirable control properties. Model airplane builders have started experimenting with this type of wing shape."

03-09-2008, 02:16 PM	#2
brian eiland Senior Member Join Date: Jul 2004 Location: Washington DC, Annapolis MD, Thailand Posts: 686	There's a paragraph at Harvard professor Michael Brenner's pages at http://www.seas.harvard.edu/brenner/Research%203.html "We have been interested in understanding the aerodynamic mechanism for this stall-delay. Recent work with Ernst van Nierop and Silas Alben demonstrates the mechanism for the observed increase in stall angle. Although the bumps have been compared to vortex generators, we propose a different mechanism: we demonstrate that the bumps alter the pressure distribution on the wing such that separation of the boundary is delayed behind bumps; this ultimately leads to a gradualonset of stall and higher stall angle. Our mechanism predicts that as the amplitude of the bumps is increased, the lift curve flattens out leading to potentially desirable control properties. Model airplane builders have started experimenting with this type of wing shape."