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

This paper introduces design and measurement principles underlying resonanc e-based pressure measurement and anemometry, emphasizing application to hig h temperature, optically opaque flows. Due to typically extreme conditions, associated high resolution anemometries have not been developed. The metho d described incorporates a novel dual-cantilever PZT-driven touch sensor, s uitable 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 t he unknown pressure(s). Design, development, and preliminary testing of the integrally important dual-cantilever touch sensor is described as are desi gn considerations specific to high temperature applications. Experimental r esults demonstrate that high-accuracy single-point pressure measurements ca n be readily obtained. In contrast, simultaneous two-point measurements wil l require experimental determination of two-dimensional calibration surface s. Two pressure measurement schemes are outlined; in the first, pressure is correlated with resonant frequency shifts at constant phase while in the s econd, pressure is related to phase shifts at constant frequency. The paper 's objectives are to introduce resonance-based pressure and velocity measur ement and to provide design and measurement guidelines which can be applied in the further development of these methods. (C) 2000 Elsevier Science Ltd .