X-38 Experimental Aeroheating at Mach 10

Details are provided of a recent effort at the NASA Langley Research Center to extend the experimental aeroheating database for the X-38 program to higher-Mach-number conditions. Global surface heat-transfer distributions were measured on 0.0177- and 0.0236-scale models of the proposed X-38 Rev 8.3 configuration at Mach 10 in air. The parametrics that were investigated primarily include freestream unit Reynolds numbers of 0.6 to 2.2 x 106/ft and body-flap deflections of 15,20, and 25 deg for an angle of attack of 40 deg. The model-scale variance was tested to obtain laminar, transitional, and turbulent heating levels on the deflected body flaps. In addition, a limited investigation of forced boundary-layer transition through the use of discrete roughness elements was performed. Comparisons of the present experimental results to computational predictions and previous experimental data were conducted. Laminar, transitional, and turbulent heating levels were observed on the deflected body flap, which compared favorably to the computational results and to the predicted heating based on the flight aerothermodynamic database.