Inverse solution of error-correction equation in surface temperature measurement using thermocouple

Purpose The purpose of this study is to address the significant temperature measurement error of thermocouples on high-temperature surfaces of aero-engines by proposing an error correction algorithm based on the inverse solution of the heat conduction differential equation in cylindrical coordinates. Design/methodology/approach A circumferentially symmetric simplified model reduced the three-dimensional heat transfer model to a two-dimensional cylindrical coordinate system. The discretization was performed using the finite volume method, and the real surface temperature was inversely deduced using an iterative inversion method. Findings It is found that the steady-state surface temperature measurement error after correction by this algorithm is controlled within 3%. The error in the thermocouple’s corrected value decreases with increasing diameter and increases with a larger contact area. The correction proves to be highly effective under quasi-steady-state and periodic temperature variation conditions. However, because of thermal response lag, certain errors persist under transient step-change conditions. Originality/value The proposed correction algorithm effectually enhances the measurement accuracy of high-temperature surface temperatures in aero-engines, thereby providing more reliable technical support for engine thermal condition monitoring and performance evaluation.