Blunt-Body Aerothermodynamic Database from High-Enthalpy Carbon-Dioxide Testing in an Expansion Tunnel

Abstract

An extensive database of heating, pressure, and flowfield measurements on a 70 deg sphere-cone blunt-body geometry in high-enthalpy carbon-dioxide flow has been generated through testing in an expansion tunnel. This database is intended to support development and validation of computational tools and methods to be employed in the design of future Mars missions. The test was conducted in an expansion tunnel in order to avoid uncertainties in the definition of freestream conditions noted in previous studies performed in reflected shock tunnels. Data were obtained across a wide range of test velocity/density conditions that produced various physical phenomena of interest, including laminar and transitional/turbulent boundary layers, nonreacting to completely dissociated postshock gas composition and shock-layer radiation. Flowfield computations were performed at the test conditions, and comparisons were made with the experimental data. Based on these comparisons, it was recommended that computational uncertainties on surface heating and pressure for laminar reacting-gas environments could be reduced to and , respectively. However, for flows with turbulence and shock-layer radiation, sufficient validation-quality data were not obtained in this study to make any conclusions with respect to uncertainties for those phenomena, which highlighted the need for further research in these areas.