Measurements and Analysis of Mars Entry, Decent, and Landing Aerothermodynamics at Flight-Duplicated Enthalpies in LENS-XX Expansion Tunnel

A new set of experimental measurements have been made in the LENS-XX expansion tunnel facility with high enthalpy carbon dioxide test gas using a 20.3-cm (8”) diameter 70 sphere-cone model. The model was tested over a wide range of conditions from 2.0 to 6.5 km/s and Reynolds numbers based on diameter from 4x10 to 1.4x10. This broad set of tunnel conditions provided characterization of the aerothermodynamic response of the sphere-cone using shock shape imaging, surface pressure, and surface heat flux. A nondimensionalization using a reference enthalpy technique was demonstrated that provides clear trends in the data as a function of freestream velocity, though collapse of the dataset is not as good as was obtained with reacting air flows in the expansion tunnel facility. Transition onset was correlated using an average !! criterion of 168. Transitional heating was compared against an existing database of perfect gas data and found to correlate similarly despite the presence of reacting carbon dioxide gas.