Improvements to the Total Temperature Calibration of the NASA Glenn Icing Research Tunnel

The ability to accurately set repeatable total temperature conditions is critical for collecting quality icing condition data, particularly near freezing conditions. As part of efforts to continually improve data quality in the NASA Glenn Icing Research Tunnel (IRT), new facility instrumentation and new calibration hardware for total temperature measurement were installed and new operational techniques were developed and implemented. This paper focuses on the improvements made in the calibration of total temperature in the IRT. Nomenclature A 0 , A 1 , A 2 RTD probe total temperature flow recovery curve fit coefficients C 0 , C 1 Test section total temperature calibration curve fit coefficients M Mach number P T Total pressure, psia P S Static pressure, psia P air Spray bar air pressure, psig t time, seconds T T Total temperature, °C (K, °F) T T,jet Total temperature of the free jet calibration facility airflow, °R T T,probe Total temperature of the probe (RTD) being calibrated, °R