Gas turbine combustor liner temperature measurement using 2D two-colour pyrometry

This study presents a two-dimensional two-colour pyrometry method developed to accurately measure the surface temperature field of gas turbine combustor liners under high-temperature operating conditions. The proposed technique addresses the limitations of conventional pointwise temperature measurements by enabling full-field thermal diagnostics based on spectral radiative properties. Grounded in Planck’s law and Wien’s approximation, the method estimates temperature using the intensity ratio between two closely spaced infrared wavelengths. A blackbody calibrator was used to compensate for sensor quantum efficiency, reflected radiation, and alignment errors, thereby deriving an adjusted emissivity ratio, . The validity and applicability of this correction were experimentally verified through a reverse-flow combustor test rig. was generally higher than 1, yielding an average value of about 1.05∼1.20. Infrared images of the liner surface were captured at various equivalence ratios, and the resulting temperature maps were compared with thermocouple data from the liner. The results showed strong agreement between the two, with deviations within 10%, confirming that the method achieves high accuracy for flat surfaces. This study demonstrates the feasibility of the non-contact, full-field temperature measurement technique and highlights its potential for real-time monitoring in aerospace propulsion and other high-temperature applications.