> Unravelling Turbulence
Unravelling Turbulence
September 27, 2007
A Simon Fraser University scientist is figuring out how to turn back the hands of time on turbulence. It’s a feat similar to making the chaotic swirls and eddies of a mountain stream unravel backwards.
While on a sabbatical at École Normale Supérieure in Paris, SFU physicist Mike Hayden and his collaborators succeeded in controlling turbulent dynamics. The latest issue of Physical Review Letters, an international journal, has just published their discovery. The editor has highlighted the article as recommended reading.
“Scientists and engineers have studied turbulence for hundreds of years, but until now the idea of trying to quite literally run things backwards has not been an option,” says Hayden.
Turbulence describes phenomena such as the wild flow of air encountered in hurricanes and tornados; large-scale whorls and swirls form and then break up into smaller and smaller eddies until all of the energy dissipates. Think of a smooth sheet of water flowing over the edge of a cliff and then breaking up into a wild and agitated torrent.
Working at temperatures close to absolute zero, Hayden and his colleagues aligned the nuclei of helium atoms and watched as they naturally formed complex, swirling, turbulent patterns. Then, using carefully designed radio signals they forced those patterns to unwind whorl by whorl, until order was established once again.
“Running these things backwards gives you a fantastic new tool for trying to understand exactly how turbulence starts and evolves,” explains Hayden. “Who knows what this could eventually lead to in terms of practical applications in industry, travel and medicine?”
Given that turbulence creates drag that can slow down cars and airplanes, this type of research could lead to more fuel-efficient vehicles. It could perhaps make golf balls less errant.
“Those dimples on a golf ball create turbulence and actually help it fly further,” says Hayden, a Vancouver resident.
Hayden has no plans to help make planes or golf balls fly backwards.
— 30 — (digital photo available on request)
While on a sabbatical at École Normale Supérieure in Paris, SFU physicist Mike Hayden and his collaborators succeeded in controlling turbulent dynamics. The latest issue of Physical Review Letters, an international journal, has just published their discovery. The editor has highlighted the article as recommended reading.
“Scientists and engineers have studied turbulence for hundreds of years, but until now the idea of trying to quite literally run things backwards has not been an option,” says Hayden.
Turbulence describes phenomena such as the wild flow of air encountered in hurricanes and tornados; large-scale whorls and swirls form and then break up into smaller and smaller eddies until all of the energy dissipates. Think of a smooth sheet of water flowing over the edge of a cliff and then breaking up into a wild and agitated torrent.
Working at temperatures close to absolute zero, Hayden and his colleagues aligned the nuclei of helium atoms and watched as they naturally formed complex, swirling, turbulent patterns. Then, using carefully designed radio signals they forced those patterns to unwind whorl by whorl, until order was established once again.
“Running these things backwards gives you a fantastic new tool for trying to understand exactly how turbulence starts and evolves,” explains Hayden. “Who knows what this could eventually lead to in terms of practical applications in industry, travel and medicine?”
Given that turbulence creates drag that can slow down cars and airplanes, this type of research could lead to more fuel-efficient vehicles. It could perhaps make golf balls less errant.
“Those dimples on a golf ball create turbulence and actually help it fly further,” says Hayden, a Vancouver resident.
Hayden has no plans to help make planes or golf balls fly backwards.
— 30 — (digital photo available on request)