The first step is to understand the evolution of the flow field, which is inherently unsteady, then use a combination of sensors and actuators to modify one of the steps in that evolutionary process. Acharya points out that high speeds are not as important in these particular applications as high Reynolds numbers. A large submarine, for instance, may generate as high Reynolds numbers when it submerges as a jet aircraft flying overhead. Using one of the department's 11 wind tunnels, Professor Mukund Acharya and his students are studying dynamic stall vortices. Suppressing or delaying this kind of vortex on a helicopter rotor or airplane wing would prevent a dynamic stall.
Students create light pulses with sound waves.
Accompanying temperatures exceed the temperature of the sun's surface. The current theory is that microshock waves inside the bubble are responsible. Conventionally, fluid dynamics researchers have been able to measure velocity at a single point. With optical techniques, Candace Wark and her students are measuring velocity at many points in a fluid flow. An atomized mixture of water and polyethylene glycol is introduced into the fluid flow.