This investigation details the design, analysis, and testing of a new, two-component wall shear gauge for three-dimensional, high-temperature flows. This gauge is a direct-measuring, nonnulling design with a round head surrounded by a small gap. Two flexure rings are used to allow small motions of the floating head. Strain gauges are mounted on the flexures, and fiber-optic displacement sensors measure how far polished faces of counterweights move in relation to a fixed housing. The strain gauges are for vah'dation of the newer fiber optics. The sensor is constructed of Haynes~® 230~®, a high-temperature nickel alloy. All components, in pure fiber-optic form, can survive to a temperature of 1073 K. The dynamic range of the sensor is from 0-500 Pa. Higher shear forces can be measured by changing the floating head size. No damping or water cooling of the sensor is required. Finite element modeling was used during the design and analysis of the sensor. Static structural, modal, and thermal analyses were performed using the ANSYS finite element package. Repeated cold-flow tests at Mach 2.4 and Mach 4.0 under high-Reynolds-number conditions have been accomplished in the Virginia Tech Supersonic Wind Tunnel. Experimental results are in excellent agreement with semiempirical prediction methods.
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