Resonance based pressure measurement and anemometry for high temperature flows: Design principles and preliminary results

This paper introduces design and measurement principles underlying resonance-based pressure measurement and anemometry, emphasizing application to high temperature, optically opaque flows. Due to typically extreme conditions, associated high resolution anemometries have not been developed. The method described incorporates a novel dual-cantilever PZT-driven touch sensor, suitable for single- and dual-point pressure measurements. The principal of operation takes advantage of the fact that pressure-induced forces on each cantilever produce resonant frequency shifts which can be correlated with the unknown pressure(s). Design, development, and preliminary testing of the integrally important dual-cantilever touch sensor is described as are design considerations specific to high temperature applications. Experimental results demonstrate that high-accuracy single-point pressure measurements can be readily obtained. In contrast, simultaneous two-point measurements will require experimental determination of two-dimensional calibration surfaces. Two pressure measurement schemes are outlined; in the first, pressure is correlated with resonant frequency shifts at constant phase while in the second, pressure is related to phase shifts at constant frequency. The paperʹs objectives are to introduce resonance-based pressure and velocity measurement and to provide design and measurement guidelines which can be applied in the further development of these methods.