Infrared thermography: An optical method in heat transfer and fluid flow visualisation

This paper deals with the evolution of infrared thermography into a powerful optical method to measure wall convective heat fluxes as well as to investigate the surface flow field behaviour over complex geometries. The most common heat-flux sensors, which are normally used for the measurements of convective heat transfer coefficients, are critically reviewed. Since the infrared scanning radiometer leads to the detection of numerous surface temperatures, its use allows taking into account the effects due to tangential conduction along the sensor; different operating methods together with their implementations are discussed. Finally, the capability of infrared thermography to deal with three complex fluid flow configurations is analysed.