DSMC Simulation Of High Temperature Chemical Non-Equilibrium Flow And Analysis Of The Aero-Optical Efect

To date, the simulation of the non-equilibrium phenomenon including chemicalreacting in high-speed fows is still a challenging work. Based on the strategy of statis-tical mechanics, DSMC (Direct Simulating Monte Carlo) is shown to be an efectivemethod in revealing the physic underlying the non-equilibrium phenomenon.In this thesis, based on the basic theory of molecular gas dynamics and chemi-cal kinetics, using the direct simulating Monte Carlo method, an efcient numericalsimulation program has been developed. And it has been used to analyze a variety ofnon-equilibrium phenomena in the fow around hypersonic vehicles.In theory, the DSMC simulation program is employed to simulate energy transferin molecular collisions, dissociation-recombination reactions, and exchange reaction-s according to the phenomenological theory proposed by Larsen and Borgnakke andother additional theory established by Bird and Boyd in a fve species mixture gas.Through the comparison of the theoretical value, it has been proved that the DSM-C simulating program used in this thesis is reliable and efective for simulating thenitrogen-oxygen dissociation reactions and the common4exchange reactions in theair.Inordertotesttheprograminamorerealisticenvironment,theHEGexperimentaldata of European Aeronautic and Space Administration has been used to verify theprogram. The results show that the DSMC simulation results are very close to theexperimental values.Based on the accurate modeling of the fow feld with chemical reactions, theaero-optical efect in such a fow feld has been analyzed in the last part of the thesis. By using the ray tracing algorithm combined with the basic principles of geometricaloptics and wave optics, the infuence on aero-optical efect causing by the chemicalreactions has been studied thought the time average fow analysis and the fuctuationfow analysis.