Integrated aeropropulsive computational fluid dynamics methodology for the Hyper-X flight experiment

Computational fluid dynamics tools have been used extensively in the analysis and development of the X-43A Hyper-X Research Vehicle. A significant element of this analysis is the prediction of integrated vehicle aeropropulsive performance, which includes an integration of aerodynamic and propulsion flowfields. The development of the Mach 7 X-43A required a preflight assessment of longitudinal and lateral-directional aeropropulsive characteristics near the target flight-test condition. The development of this preflight database was accomplished through extensive aerodynamic wind-tunnel testing and a combination of three-dimensional inviscid airframe calculations and cowl-to-tail scramjet cycle analyses to generate longitudinal performance increments between mission sequences. These increments were measured directly and validated through tests of the Hyper-X flight engine and vehicle flowpath simulator in the NASA Langley Research Center 8-Foot High Temperature Tunnel. Predictions were refined with tip-to-tail Navier-Stokes calculations, which also provided information on scramjet exhaust plume expansion in the aftbody region. A qualitative assessment of lateral-directional stability characteristics was made through a series of tip-to-tail inviscid calculations, including a simulation of the powered scramjet flight-test condition. Additional comparisons with wind-tunnel force and moment data as well as surface pressure measurements from the Hyper-X flight engine and vehicle flowpath simulator model and wind-tunnel testing were made to assess solution accuracy.