Experimental and software tools to forecast radiative and conductive thermal transfer in partially transparent material deposed on rotating blades for turbine engine

The optimisation study of thermal barrier coatings on rotating blades for turbine engine needs the building of specific devices adapted for thermal characterization of partially transparent ceramic. We have designed two methods for measuring thermal proprieties of thin films. The first one allows measuring the thermal diffusivity and the specific heat at high temperatures. This apparatus adapted for partially transparent ceramic is based on the flash diffusivity principle. The second device has been built to measure the emissivity and the absorption coefficient of partially transparent ceramics. ition, software has been developed, it allows with the thermal proprieties measured, forecasting the temperature evolutions of a sample or a bi-layer structure. This software is a very useful tool to understand the physical phenomena inside a semi-transparent material. It helped to set the experimental conditions and to define a method that provides a satisfactory accuracy in the measurement of the thermal diffusivity. In addition, it allows forecasting the temperature distribution inside a blade exposed to radiation from a combustor.