Recovery Characteristics of a Single-Shielded Self-Aspirating Thermocouple Probe at Low Pressure Levels and Subsonic Speeds

摘要

An apparatus which produces a well-defined flow field for calibration of thermocouple probes over a wide range of subsonic flow conditions at low pressure levels is described. Results for calibration of a typical thermocouple probe used in engine testing are presented. Temperature recovery characteristics are presented for a thermocouple probe of the single-shielded, self-aspirating type for total pressures of 0.75, 1.0, 3.0, 7.5, and 15 psia with subsonic flow speeds ranging from Mach number 0.25 to Mach number 1.0. The total temperature of the air was approximately 670R for all tests. An analysis of the probe recovery characteristics based on a semi-empirical correlation was made, and the correlation appears to give satisfactory results over the entire Mach number and total pressure range considered. (Author)