Quantitative Global Heat-Transfer Measurements using Temperature-Sensitive Paint on a Blunt Body in Hypersonic Flows

Abstract

A quantitative global intensity-based temperature-sensitive paint heat-transfer measurement system has been developed for use in the US Air Force Hypervelocity Wind Tunnel No. 9. Several data reduction approaches have been proposed for calculating the convective heat flux from the temperature-sensitive paint emission intensity data. The validity of the underlying assumptions and the sensitivity of the algorithms to perturbations in various system parameters have been analyzed numerically. Finally, the temperature-sensitive paint emission intensity data have been collected on a model of a NASA Crew Exploration Vehicle capsule in Mach 10 flow. The proposed data reduction algorithms have been applied to obtain an estimate of the thermal conductivity of the coating as a function of temperature and to generate high-resolution quantitative heat-transfer maps of the model's heat shield. On the majority of the heat shield surface, a good agreement between the heat-transfer maps and the baseline conventional instrumentation data has been revealed.