RAREFIELD GAS FLOW EFFECTS ON HYPERSONIC VEHICLES

BASED UPON A PRELIMINARY LITERATURE SEARCH, SEVERAL POSSIBLE AREAS FOR FUTURE RESEARCH WERE IDENTIFIED. FIRST, THERE APPEARS TO BE NO PUBLISHED IDENTIFICATION OF THE RAREFIELD FLOW REGIMES, AND CRUCIAL RAREFIELD FLIGHT REGIMES, FOR VARIOUS VEHICLES IN DESIRED HIGH ALTITUDE MANEUVERS. SECOND, IT SEEMS CLEAR THAT CONTINUUM ANALYSES HAVE SHORTCOMINGS IN CERTAIN FLIGHT REGIMES AND RAREFIELD FLOW ANALYSES, SUCH AS MONTE CARLO SIMULATIONS, ARE NECESSARY BUT NO ATTEMPT IN EVIDENCE TO PROVIDE A MATCHING PROCESS BRINGING COMPUTATIONS FOR CONTINUUM AND RAREFIELD REGIONS TOGETHER. THIRD, MONTE CARLO SIMULATION SEEM TO BE CABLE OF COMPUTING PROPERTIES IN RAREFIELD FLOW REGIONS WITH A WIDE RANGE OF FEATURES, SUCH AS CHEMICAL REACTIONS, WITHOUT MAJOR MODIFICATIONS. HOWEVER, BIRD (1985) STATES THAT THE NECESSARY DATABASE IS DEFICIENT. THIS PROPOSAL SUGGESTS ADDITIONAL LITERATURE SEARCHES IN MOST OF THESE AREAS. IN ADDITION, IT IS PROPOSED TO INITIATE FORMULATION OF A METHOD OF MATCHED ASYMPTOTIC EXPANSIONS TO DEVELOP A MATCHING PROCEDURE TO UNIFY THE COMPUTATION OF RAREFIELD AND CONTINUUM FLOW REGIONS. FURTHER SUGGESTIONS WERE MADE FOR RAREFIELD AND CONTINUUM FLOW ANALYSES OF SHOCK STRUCTURE AND FOR EXTENSIONS TO THE CAPABILITY OF MONTE CARLO SIMULATIONS.