Plasma-Assisted Local Control and Energy Management in a Scramjet Flowpat

The effort to develop viable hypersonic air-breathing propulsion can benefit considerably from implementation of revolutionary techniques based on plasma-fluid interactions. Simulations have a key role to play in this endeavor because of difficulties encountered in testing under the severe operating environments. To this end, challenge resources have been utilized to perform pathfinding high-fidelity, fully three-dimensional (3-D) multiphysics simulations on critical problems encountered in scramjet flowpaths. The effort has demonstrated several local flow control concepts as well as large scale energy management. In the local flow control category, a novel electrodeless approach is shown to successfully accomplish suppression of shock-induced turbulent separation. In other sub-component studies, the nonintuitive effect of plasma-based force and heating on a compressible inviscid instability is analyzed, near-wall sheath phenomena are elucidated and losses due to vibrational freezing in a nozzle are characterized from first-principles. For energy management, prior tip-to-tail simulations on rectangular scramjets have been complemented and compared with a new axisymmetric design, utilizing azimuthally oriented magnetic fields. In both, viscous-inviscid interactions, velocity distortions and Hall currents are first order effects, but spanwise asymmetries observed in the rectangular cross-section design are precluded in the axisymmetric configuration. These analyses, which require massive computational resources obtained through the DoD HPCMP, demonstrate the key role of simulations in leading the development of future hypersonic vehicles utilizing advanced concepts.