Impact of specific heat ratio on aerodynamic characteristics of Viking in hypersonic entry to Mars

摘要

The poor understanding of Martian atmosphere will affect therncomputational results of aerodynamic characteristics of Mars entry vehicles. ThreedimensionalrnNavier-Stokes equations using perfect gas model and real gas modelsrnare solved to predict aerodynamic characteristic of Viking in hypersonic entry, tornanalyze the effect of specific heat ratio. The results show that current physicalrnchemical models and numerical methods could produce well-matched aerodynamicrnforce coefficients in comparison with flight data; specific heat ratio do havernconsiderable influence on aerodynamic force, smaller specific heat ratio producesrnbigger absolute value of axial and normal force; perfect gas with effective specificrnheat ratio derived from density ratio results in the most close data to real gas.