As the field of hypersonic vehicle design develops, having shear stress data can aid in the minimization of
drag source effects and verify results from computational fluid dynamics simulations. Transducer size,
placement, and narrow bandwidth currently limit accurate shear stress measurements due to the small
length and time scales seen in turbulent fluid motion and the issue of flow disruption. Shock wave and
boundary layer effects also produce large thermal loads in hypersonic flows. The proposed research plan
Drs. Cattafesta and Sheplak focus on experimental acoustics and fluid dynamics research, with particular emphasis on the modeling, development, and implementation of MEMS sensors and actuators for fundamental studies and active control research. Sensor development activities include microphones for directional acoustic arrays and unsteady pressure transducers for turbulent boundary layer studies as well as for feedback sensing for flow control. We are also developing shear stress sensors for time resolved shear stress measurements. Actuator technology includes piezoelectric and electrodynamic zero-net mass-flux (i.e., synthetic jets) and plasma type devices. Our active flow control research focuses on adaptive feedback flow control with applications to circulation control, flow separation control, and cavity flow oscillations. Our aeroacoustics research focuses on acoustic liner technology and fundamental studies and mitigation of airframe noise studies (e.g., trailing edge noise, landing gear, circulation control, etc.) in our 29 in. x 44 in. x 72 in. (75 m/s max) open-jet anechoic wind tunnel located inside a 100 Hz cutoff anechoic chamber. Finally, we are developing ultrasonic transducers for proximity sensing, parametric acoustic arrays, and biomedical imaging.