An experimental investigation of heat transfer from a highly cooled turbulent boundary layer

Abstract

Shocktube measurements of turbulent heat transfer in supersonic, dissociated air and in the presence of a zero pressure gradient are presented for incident shock velocities from 3 to 6 mm//zsec and initial driven tube pressures of 5, 8, 10, and 20 mm Hg. These data were obtained using platinum calorimeter gages positioned on the inside surface of a sharp leadingedge hollow cylinder with its axis aligned parallel to the frees tream flow. The range of conditions included Reynolds numbers from approximately 10 to 1.4 X 10, total enthalpies simulating flight velocities up to 8 km/sec, and walltoadiabaticwall enthalpy ratios from 0.01 to 0.04. Two-dimensional roughness elements were used to trip the boundary layer. The data obtained are compared with a number of existing techniques for the prediction of turbulent heating. Although the data was obtained at conditions outside of the range on which the method of Spalding and Chi is based, reasonable agreement with this method is shown to exist. Comparisons of existing methods of prediction are also made with other experimental data available from the literature.