Hypersonic shock-wave/boundary-layer interactions on a cone/flare

Time-resolved surface temperature measurements have been carried out on a 7 degrees half-angle circular cone/flay model in the Air Force Research Laboratory's Mach-6 Ludwieg Tube using infrared thermography. Measurements were performed at zero angle of attack on a total of 16 different nose bluntness/flare angle geometries at three different freestream unit Reynolds numbers. The boundary layer entering the interaction region was turbulent for the two sharper nosetips and laminar for the two blunter nosetips. Stanton-number contours and profiles were used to investigate the effect of nose bluntness, flare angle, and freestream unit Reynolds number on the length of boundary-layer separation and the peak heating achieved upon reattachment. The classical scaling analyses of Souverein et al. and Hung & Barnett for separation length and peak heating, respectively, have been extended for the use of axisymmetric cone/flare shock-wave/boundary-layer interactions. Scaling the peak heating with the density ratio across the separation shock wave, instead of the pressure ratio, significantly improves/simplifies the analysis.