Experimental application of a novel set up apparatus for spectral emissivity characterization at high temperature for Thermal Protection System

The spectral emissivity behaviour of the materials is a fundamental feature to be known in evaluating their usability as Thermal Protection System (TPS) of space vehicles. The emissivity affects the heat transmission performances of the TPS and its spectral trend has a not negligible impact on the accuracy of the dual color radiometric technique used for monitoring the temperature during the re-entry tests performed in the Plasma Wind Tunnel.In this work a novel set up, based on the combined use of different optical devices operating in different spectral ranges, was employed to characterize the spectral emissivity of the Ceramic Matrix Composites (CMC) ISiComp®, an innovative CMC with long C fibres and SiC matrix, developed by the Italian Aerospace Research Centre (CIRA) and PETROCERAMICS. The ISiComp emissivity characterization was performed from 450 °C up to 850 °C at different wavelengths, ranging from 1.5 μm to 14 μm.