Calibration of multi-hole probes for measurements in compressible organic vapor flows

Abstract

Multi-hole probes are necessary devices to measure flow characteristics and losses in turbomachinery. The present contribution reports the first experience with calibrating and using multi-hole probes in high-speed flows of the organic vapor Novec 649 at elevated pressure and temperature levels. It is found that the classical scheme, established for perfect gas applications, must be extended by an additional quantity reflecting the impact of the initial thermodynamic state on the pressure signals and the data reduction. The practical use and operational issues of three- and five-hole probes for ORCturbomachinery research are discussed based on the new results. A promising hybrid experimentalnumerical calibration approach significantly reduces the tremendous calibration effort.