Micro-electro-mechanical-systems direct fluid shear stress sensor arrays for flow control

The design and analysis of non-intrusive micro-electro-mechanical-systems sensors to measure fluid shear stress on the wing surface of a commercial jetliner is presented. A design specification is derived from analysis of flight loading data using computational fluid dynamics. The specification accounts for different flight conditions, aerodynamic smoothness and sensor bandwidth. Capacitive and PZT-based direct fluid shear sensor designs based upon the force-displacement relationship of a tethered plate are created. The sensors have overall dimensions <0.7 mm, can be collated into large arrays and provide scaled digital outputs, and their design methodology is easily generalized to similar applications.