ABSTRACT

Thermography is a measurement technique of thermal maps. Accurate quantitative analysis of thermal images acquired in real time is an essential performance requirement of a thermographic system. In particular, infrared (IR) thermography can be fruitfully employed to measure convective heat fluxes, in both steady and transient techniques. The use of IR thermography allows not only measurement of the distribution of local heat-transfer coefficients but also visualization of the local flow condition, that is, in particular, the location of the boundary-layer transition and the location and extent of the flow-separation region. A particular application of IR thermography is related to the development of advanced gas-turbine combustion systems. In addition to developing a valuable pool of wall-cooling design information, performance data acquired by IR thermography were used to benchmark temperature-prediction computer codes. Satisfactory agreement was obtained between the code predictions and the thermography measurement.