Calibration of CFD Methods for High Mach Number Aeroengine Flowfields

Abstract

The design and analysis of scramjet engines relies heavily on the use of Computational Fluid Dynamics (CFD) methods due to the lack of experimental facilities and engineering analysis techniques for high Mach number, high-temperature flows. This emphasis on CFD requires that the methods be calibrated through comparison with existing experimental data to determine their level of capability and range of applicability. At General Dynamics’ Fort Worth Division a level of confidence has been established in the use of CFD methods for scramjet flowfields. These methods include a Beam-Warming-based Unsteady Navier-Stokes (UNS) solver, a Beam-Warming-based Parabolized Navier-Stokes (PNS) solver, and a MacCormack-based PNS solver. Specifically, comparisons between CFD flowfields and experimental data for a blunt cone at Mach 10.6, an inlet at Mach 7.4, a combustor at Mach 2.4, and an axisymmetric plug nozzle at Mach 3.2 have been made. These calibrations show good overall agreement for wall pressures, integrated forces, and pressure, Mach number, and chemical species profiles. Examination of the disparities between the CFD and experimental results focuses concern on the treatment of boundary layer turbulence and finite rate chemistry. As a result, further developmental tasks are suggested, which, when complete, will further enhance the applicability of the subject CFD methods.