MIT scientists find a way using golf ball-like morphable surfaces, to reduce drag and improve efficiency of vehicles. Image © MIT Watch the video…
Studies of aerodynamics have shown that while a ball with a dimpled surface, has half the drag of a smooth one at lower speeds, at higher speeds that advantage reverses.
So the ideal would be a surface whose smoothness can be altered, and this is what the MIT researchers developed.
In the lab, the morphable surface can have its surface texture changed at will, simply by changing the pressure inside, using a pump.
When the inside preassure is reduced, the flexible material shrinks, but the outer layer, being stiffer, gets wrinkled as it shrinks, just ‘like a plum drying in the sun to become a prune.’
Reis, an assistant professor of mechanical engineering and civil and environmental engineering, said:
“Numerous studies of wrinkling have been done on flat surfaces Less is known about what happens when you curve the surface. How does that affect the whole wrinkling process?”
We realized that these samples look just like golf balls.We systematically tested them in a wind tunnel, and we saw a reduction in drag very similar to that of golf balls.”
John Rogers, a professor of materials research and engineering at the University of Illinois at Urbana-Champaign who was not involved in this work, said:
“It represents a delightful example of how controlled processes of mechanical buckling can be used to create three-dimensional structures with interesting aerodynamic properties. The type of dynamic tuning of sophisticated surface morphologies made possible by this approach would be difficult or impossible to achieve in any other way.”
Read more: mit.edu