Catalytic Effects on Heat Transfer Measurements for Aerothermal Studies with CO2

An investigation has been performed at CUBRC using the LENS facilities to study the behavior of surface heating augmentation due to catalytic surface recombination for carbon dioxide and air test gases. Three types of heat transfer instrumentation have been employed on a model that shows definitive heating enhancement which can only be caused by the effect of surface catalysis. The measured heat transfer data from all types of instrumentation correlate well with CFD predictions in baseline non-catalytic flows, but show consistently higher heating levels than can be predicted with a non-catalytic wall in a catalytic environment. A similar effect has been documented in air with atomic oxygen and nitric oxide recombination. The successful demonstration and understanding of this behavior is critical to optimum heat shield/TPS systems design for future Martian entry applications. I.