The New Math For Turbulent Flow

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Inspiration sometimes comes from unusual sources and a Princeton University scientist's examination of the air flow through a car's sunroof may someday make jet engines quieter, speed up stealth aircraft and make better micro air vehicles. What Clarence Rowley has demonstrated, through a Princeton-worthy series of calculations and experimentation, is that the sound created by the turbulence at the barrier between slow and fast moving air can be cancelled in much the same way that noise-attenuating headsets give pilots a quieter ride. Using wind tunnels and models resembling a car sunroof, Rowley analyzed the forces responsible for the wind noise that leads many of us to wonder why automakers would cut holes in the roof in the first place. Then, he installed a microphone to channel the noise through a computer which, using those calculations, offered an equal and opposite response to an accompanying speaker, thus canceling the noise. "The physical mechanism is actually very simple," Rowley said. The same setup can be applied to jet engines and the bomb bay doors on aircraft, but Rowley is concentrating on applying the technique to create model-size aircraft that fly as fast as birds but maneuver with the agility of insects. We wonder what that equation looks like...