Shear Sensors for High Speed, High Temperature Flow Applications

ABSTRACT: The principal thrust of the proposed research is the development and testing of a high-speed (MHz range) sensor for measuring the shear stress beneath a hypersonic boundary layer at elevated temperatures. The development of such a sensor will enable the Air-Force to develop more robust empirical models for predicting the wall shear stress in complex 3-D flows. The proposed sensor innovation uses high temperature ferroelectric materials to measure pressure and shear stress across two dimensions. This approach leverages micromachining (i.e., MEMS) processing techniques and aims to achieve all critical Air Force specifications including broadband response to 1-MHz frequencies at high operating temperatures (up to 1,200 K). Testing will be performed using aerodynamic facilities at The University of Texas at Austin. BENEFIT: There is presently a lack of sensors capable of directly measuring shear under the extreme flow conditions encountered in advanced vehicles like the HIFiRE, X-51. The proposed innovation aims to alleviate this void in the form of a compact, robust, broadband shear sensor. The application pool is broad and encompasses the development of advanced weaponry, supersonic combustion, or simply innovative diagnostic tools for test facilities like AEDC.