Determination of the stagnation temperature of high-enthalpy supersonic air flows using a thermoelectric transducer with shielded measuring junction
M.V. Ananyan, V.Yu. Aleksandrov, K.Yu. Arefiev
Baranov Central Institute of Aviation Motors, Moscow, Russia
Keywords: stagnation temperature, high-enthalpy stream, supersonic flow, measurement, thermoelectric transducer, shielded measuring junction
Abstract
Methodological aspects of stagnation-temperature measurement in high-enthalpy supersonic air flows using a thermoelectric transducer (thermocouple) with shielded measuring junction are analyzed. Specific features of thermo- and gas-dynamic processes under the conditions of interest, leading to a substantial deviation of temperatures measured using traditional measuring methods from the true temperatures, are demonstrated. Refinements to the method of determining the temperature of high-enthalpy supersonic air flows allowing one to reduce the deviation from the true temperature are introduced. A mathematical apparatus developed for analysis of experimental data and for quantitative estimation of temperature-measurement error is described. Approbation of the proposed approaches and validation of the developed mathematical models are performed using the results of experimental studies of high-enthalpy supersonic flows. A satisfactory agreement between the results of indirect temperature measurements and specified temperature values is shown. The results of the study can prove useful in the development of techniques and methods, and in the analysis of physical experiments with high-enthalpy flows.
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