Heat transfer modelling of radiant flux from a halogen lamp for enhancing Infrared thermography simulation

Abstract

InfraRed Thermography (IRT) is widely used in Non-Destructive Evaluation (NDE) for its ability to provide real-time, two-dimensional, non-contact measurements of heat distribution. Enhancing the analysis of thermal results requires a comprehensive understanding of the entire measurement chain from the heat source, through propagation, to detection, signal processing and data interpretation, which demands an effective combination of simulation and experimental approaches. This study presents the modelling of heat transfer, with particular emphasis on accurately characterising the radiant heat flux emitted by a halogen lamp. A fluxmeter sensor was employed to measure the radiant heat flux at different distances and spatial locations. Subsequently, 3D heat transfer models incorporating these heat sources were established and applied to an Acrylonitrile Butadiene Styrene plate to investigate thermal behaviour and the influence of factors within the measurement chain. Critical parameters were also considered, including thermal conductivity, convective heat transfer coefficients, fluxmeter sensor sensitivity, heat flux characteristics and measurement methods. Simulation results were validated against experimental data using both an infrared camera and a pyrometer and demonstrated strong agreement. Relative errors were below 4.2 % for pyrometer measurements, whereas slightly higher errors, up to 5.9 % for IRT method, which is mainly attributed the influence of environmental factors on this technique. These findings confirm the accuracy and reliability of the calibrated heat source and modelling parameters. Integrating experimental data into the thermal simulation enhances both accuracy and consistency, thereby establishing a more robust framework for the application of numerical methods throughout the IRT measurement chain in NDE applications.