Aeroheating testing and predictions for Project Orion Crew Exploration Vehicle

An investigation of the aeroheating environment of the Project Orion Crew Exploration Vehicle was performed in the Arnold Engineering Development Center Hypervelocity Wind Tunnel 9 Mach 8 and Mach 10 nozzles and in the NASA Langley Research Center 20-Inch Mach 6 Air Tunnel. Heating data were obtained using a thermocoupleinstrumented ∼0.035-scale model [0.1778 m (7 in.) diameter] of the flight vehicle. Runs were performed in the Tunnel 9 Mach 10 nozzle at freestream unit Reynolds numbers of 1 × 10⁶ to 20 × 10⁶/f t, in the Tunnel 9 Mach 8 nozzle at freestream unit Reynolds numbers of 8 × 10⁶ to 48 × 10⁶/f t, and in the 20-Inch Mach 6 Air Tunnel at freestream unit Reynolds numbers of 1 × 10⁶ to 7 × 10⁶/f t. In both facilities, enthalpy levels were low and the test gas (N₂ in Tunnel 9 and air in the 20-Inch Mach 6 Air Tunnel) behaved as a perfect gas. These test conditions produced laminar, transitional, and turbulent data in the Tunnel 9 Mach 10 nozzle; transitional and turbulent data in the Tunnel 9 Mach 8 nozzle; and laminar and transitional data in the 20-Inch Mach 6 Air Tunnel. Laminar and turbulent predictions were generated for all wind-tunnel test conditions, and comparisons were performed with the experimental data to help define the accuracy of the computational method. In general, it was found that both laminar data and predictions and turbulent data and predictions agreed to within less than the estimated ±12% experimental uncertainty estimate. Laminar heating distributions from all three data sets were shown to correlate well and demonstrated Reynolds numbers independence when expressed in terms of the Stanton number based on adiabatic-wall-recovery enthalpy. Transition-onset locations on the lee-side centerline were determined from the data and correlated in terms of boundary-layer parameters. Finally, turbulent heating augmentation ratios were determined for several body-point locations and correlated in terms of the boundary-layer momentum Reynolds number.