Opportunity at Air Force Research Laboratory (AFRL)
Computation of Supersonic and Hypersonic Flow Phenomena and their Control
Aerospace Systems Directorate, RQ/Aerospace Structures, Aerodynamics, and Flight Controls
||Wright-Patterson AFB, OH 454337542
Improved supersonic flight and space-access capability with air-breathing hypersonic trajectories are key elements of many future technology development programs because of their profound impact on commercial and military activities. Significant basic research challenges remain to be overcome in these areas, ranging from developing theories of transition and turbulence to predicting and managing the aerothermal and propulsion environment and determining non-continuum effects. Given the daunting difficulty of reproducing flight conditions in ground-test facilities, simulations necessarily play an integral role in design and development. High-fidelity computations of high-speed flows are very challenging because of the fundamentally multidisciplinary and three-dimensional nature of the problem. In addition to viscous fluid dynamics, it is often essential to consider turbulence and thermochemical non-equilibrium effects such as vibrational excitation, dissociation, ionization, and combustion. Therefore, formulations must be extended to include the master equation for treating the various energy exchange processes of the internal energy states in high temperature air. The combined phenomena yield a large, stiff set of nonlinear governing equations, which must be resolved with fine spatio-temporal discretizations. Thus, it is essential to develop highly accurate physical models and to couple them to advanced, robust numerical methods which can exploit massively parallel modern computational systems. Broad research opportunities exist to (1) develop and implement highly accurate algorithms for a hierarchy of theoretical models of increasing fidelity with and without the continuum approximation; (2) utilize computational tools to investigate a variety of physical phenomena, including direct numerical simulations of supersonic and hypersonic transition and turbulence, thermochemical nonequilibrium phenomenon, and shock/boundary layer interactions; (3) develop, implement, and validate models for state-to-state kinetics; and (4) explore drag reduction and thermal protection techniques through flow control.
Algorithms; Hypersonic aerodynamics; Shock waves; Computational fluid dynamics; Aerothermodynamics; Thermochemical nonequilibrium, Atmospheric boundary layers;
Open to U.S. citizens and permanent residents