HYPERSONIC ANALYSIS FOR VEHICLES IN THE CONTINUUM-TRANSITIONREGIME

SEVERAL AEROSPACE VECHICLES ARE CURRENTLY BEING CONSIDERED THAT HAVE A SIGNIFICANT PORTION OF THEIR FLIGHT PATH IN THE UPPER REACHES OF THE ATMOSPHERE. THE FLOW ABOUT THESE VEHICLES IS IN THE CONTINUUM-TRANSITION REGIME WHERE THE STANDARD EQUATIONS OF CONTINUUM FLOW, THE NAVIER-STOKES EQUATIONS, BEGIN TO FALL. THIS PROJECT WILL MODIFY THE HANA CODE, AN EXISTING NAVIER-STOKES CODE FOR THE ANALYSIS OF HYPERSONIC VEHICLES TO SOLVE THE BURNETT EQUATIONS WITH COUPLED, ROTATIONAL NONEQUILIBRIUM. THE BURNETT EQUATIONS ARE MORE ACCURATE THAN THE NAVIER-STOKES EQUATIONS FOR LOW-DENSITY FLOWS WITH FINITE THICKNESS SHOCKS. SOLUTIONS TO THE BURNETT EQUATIONS HAVE ONLY RECENTLY BEEN OBTAINED FOR THE HYPERSONIC FLOWS. THE PHASE I INVESTIGATION WILL DETERMINE THE VIABILITY OF SOLVING THE BURNETT EQUATIONS WITH COUPLED, ROTATIONAL, NONEQUILIBRIUM AND SURFACE-SLIP BOUNDARY CONDITIONS WITHIN THE HANA CODE. IN PARTICULAR, THE RAMIFICATIONS OF USING UPWIND DIFFERENCING OF THE INVISCID FLUXES AND DIAGONALIZED VISCOUS JACOBIANS IN THE LU-SGS IMPLICIT METHOD WILL BE STUDIED. THE PROPER IMPLEMENTATION OF SURFACE-SLIP BOUNDARY CONDITIONS WILL ALSOBE CONSIDERED. SEVERAL AEROSPACE VECHICLES ARE CURRENTLY BEING CONSIDERED THAT HAVE A SIGNIFICANT PORTION OF THEIR FLIGHT PATH IN THE UPPER REACHES OF THE ATMOSPHERE. THE FLOW ABOUT THESE VEHICLES IS IN THE CONTINUUM-TRANSITION REGIME WHERE THE STANDARD EQUATIONS OF CONTINUUM FLOW, THE NAVIER-STOKES EQUATIONS, BEGIN TO FALL. THIS PROJECT WILL MODIFY THE HANA CODE, AN EXISTING NAVIER-STOKES CODE FOR THE ANALYSIS OF HYPERSONIC VEHICLES TO SOLVE THE BURNETT EQUATIONS WITH COUPLED, ROTATIONAL NONEQUILIBRIUM. THE BURNETT EQUATIONS ARE MORE ACCURATE THAN THE NAVIER-STOKES EQUATIONS FOR LOW-DENSITY FLOWS WITH FINITE THICKNESS SHOCKS. SOLUTIONS TO THE BURNETT EQUATIONS HAVE ONLY RECENTLY BEEN OBTAINED FOR THE HYPERSONIC FLOWS. THE PHASE I INVESTIGATION WILL DETERMINE THE VIABILITY OF SOLVING THE BURNETT EQUATIONS WITH COUPLED, ROTATIONAL, NONEQUILIBRIUM AND SURFACE-SLIP BOUNDARY CONDITIONS WITHIN THE HANA CODE. IN PARTICULAR, THE RAMIFICATIONS OF USING UPWIND DIFFERENCING OF THE INVISCID FLUXES AND DIAGONALIZED VISCOUS JACOBIANS IN THE LU-SGS IMPLICIT METHOD WILL BE STUDIED. THE PROPER IMPLEMENTATION OF SURFACE-SLIP BOUNDARY CONDITIONS WILL ALSOBE CONSIDERED.