TY - JOUR
T1 - Infrared temperature measurements on fast moving targets
T2 - A novel calibration approach
AU - Sisti, Manuela
AU - Falsetti, Chiara
AU - Beard, Paul F.
PY - 2024
Y1 - 2024
N2 - In this study, an infrared system is developed for accurate measurements of surface temperature and heat transfer on fast moving targets. The system was designed for the Oxford Turbine Research Facility, a world-leading experimental facility delivering highly engine representative, scalable heat transfer results for aerospace research. Infrared thermography is employed to acquire temperature maps of high-pressure turbine blades, allowing assessment of surface thermal conditions including heat transfer coefficient, adiabatic wall temperature, Nusselt number, cooling effectiveness, and metal effectiveness. Achieving accurate infrared thermography measurements in rotating turbomachinery experimental conditions is arduous due to reflections from the surroundings, low emissivity of metallic parts, and motion blur resulting from high speed. To overcome these challenges, calibration procedures were developed against a traceable standard using a bespoke steady experimental facility. A method to determine the reflected temperature from surroundings was also validated. Correction for all measurement disturbances is demonstrated to within the accuracy of the primary measurement thermocouple. Finally, the developed calibration method was validated on a fast-moving rotating geometry demonstrating accurate correction for all measurement disturbances, without the need for an in situ calibration. A detailed uncertainty analysis for each calibration step is also presented.
AB - In this study, an infrared system is developed for accurate measurements of surface temperature and heat transfer on fast moving targets. The system was designed for the Oxford Turbine Research Facility, a world-leading experimental facility delivering highly engine representative, scalable heat transfer results for aerospace research. Infrared thermography is employed to acquire temperature maps of high-pressure turbine blades, allowing assessment of surface thermal conditions including heat transfer coefficient, adiabatic wall temperature, Nusselt number, cooling effectiveness, and metal effectiveness. Achieving accurate infrared thermography measurements in rotating turbomachinery experimental conditions is arduous due to reflections from the surroundings, low emissivity of metallic parts, and motion blur resulting from high speed. To overcome these challenges, calibration procedures were developed against a traceable standard using a bespoke steady experimental facility. A method to determine the reflected temperature from surroundings was also validated. Correction for all measurement disturbances is demonstrated to within the accuracy of the primary measurement thermocouple. Finally, the developed calibration method was validated on a fast-moving rotating geometry demonstrating accurate correction for all measurement disturbances, without the need for an in situ calibration. A detailed uncertainty analysis for each calibration step is also presented.
KW - High-speed target
KW - Infrared thermography
KW - Measurement advancements
KW - Turbomachinery
UR - http://www.scopus.com/inward/record.url?scp=85180568312&partnerID=8YFLogxK
U2 - 10.1016/j.measurement.2023.113870
DO - 10.1016/j.measurement.2023.113870
M3 - Article
AN - SCOPUS:85180568312
SN - 0263-2241
VL - 225
JO - Measurement: Journal of the International Measurement Confederation
JF - Measurement: Journal of the International Measurement Confederation
M1 - 113870
ER -