High-enthalpy and perfect-gas heating measurements on a blunt cone

TLDR: In this article, a 70-deg sphere-cone configuration model and the wake of the model on the sting were used to study the wake flow establishment process in a high-enthalpy impulse facility and a conventional perfect-gas air wind tunnel.

Abstract: Detailed aerodynamic heating measurements were made on a 70-deg sphere-cone configuration model and in the wake of the model on the sting. Tests were conducted in hypersonic flows in a high-enthalpy impulse facility, in which air and carbon dioxide were employed as test gases, and in a conventional perfect-gas air wind tunnel. Heating data were also obtained on three similar parametric forebody configurations. Normalized forebody Stanton number distributions were independent of Reynolds number and test gas, with the exception of smaller forebody corner heating peaks in carbon dioxide. Peak wake Stanton numbers were 5% of the forebody stagnation point values in the high-enthalpy tests and varied with Reynolds number from 7 to 15% of the stagnation point values in the perfect-gas tests. The impulse facility wake flow establishment process was studied in detail, and a criterion for determining when the wake flow becomes established was developed. Wake flow establishment was found to require on the order of 45-75 flow-path lengths as based on the model size and freestream velocity. Nomenclature C = ^Too/^ooT-* CH = Stanton number, q/[pooUoo(ho — hw)] cp = specific heat, J/kg-K h = enthalpy, J/kg k = thermal conductivity, W/m-K L = surface distance along sting from model base, m Q - heat energy, J/m2 q = heat transfer rate, W/m2