ANALYSIS OF FLOWFIELDS AROUND HYPERVELOCITY VEHICLES IN LOW-TO-HIGH DENSITY FLIGHT REGIME

THE HYPERSONIC VEHICLES FLYING AT HIGH ALTITUDES OPERATE IN A FLOW REGIME WHERE THE NONCONTINUUM EFFECTS NEAR THE SURFACE AND FINITE SHOCK THICKNESS DUE TO LOW DENSITY MAKE THE CONVENTIONAL CONTINUUM TECHNIQUES GROSSLY INADEQUATE. CHEMICAL NONEQUILIBRIUM IS ALSO IMPORTANT UNDER THE LOW-DENSITY FLOW CONDITIONS. UNTIL RECENTLY NOT MUCH WORK HAS BEEN DONE TO EVALUATE DEFICIENCIES OF THE EXISTING CONTINUUM TECHNIQUES TO ANALYZE THE LOW-DENSITY FLOWS AND FIND MEANS TO REMOVE THEM. RECENTLY COMPLETED DETAILED WORKBY THE PRINCIPAL INVESTIGATOR SUGGESTS THE WAYS AND MEANS TOEVOLVE AND EFFICIENT AND PRACTICAL CONTINUUM COMPUTATIONAL TECHNIQUE. THIS TECHNIQUE WOULD BE CAPABLE OF HANDLING CHEMICAL NONEQUILIBRIUM, FINITE SURFACE CATALYCITY, AND HIGHLY TEMPERATURE-DEPENDENT TRANSPORT AND THERMODYNAMIC PROPERTIES FOR DISSOCIATED AIR UNDER THE LOW-DENSITY FLIGHT CONDITIONS. DUE TO THE HIGHLY ENERGETIC NATURE OF THE FLOWSAROUND SOME OF THE HYPERSONIC VEHICLES, IT BECOMES IMPORTANTTO INCLUDE RADIATION ALSO IN THESE CALCULATIONS WITH SOME ALLOWANCE FOR THERMAL NONEQUILIBRIUM. THE EXISTING CONTINUUM TECHNIQUES ALSO PERFORM POORLY IN PREDICTING FLOWS WITH REAL GAS PHYSICS AROUND NARROW-ANGLE BODIES AT LOWER ALTITUDES (OR HIGHER DENSITIES). THE SUGGESTED RESEARCH OVERCOMES THIS SHORTCOMING AS WELL.