N2-CH4-Ar Chemical Kinetic Model for Simulations of Atmospheric Entry to Titan

Abstract

A detailed chemical kinetic model for N 2 -CH 4 -Ar mixtures is developed for nonequilibrium simulation of shock layers formed in front of probes entering Titan's atmosphere. The detailed kinetic model uses up-to-date chemical reaction mechanisms and reaction rates, and it is validated against existing shock tube experiments. A reduced kinetic model is also developed through sensitivity analysis of chemical reactions in the detailed model and reproduces the chemical kinetics of major species within the parameter space that may be encountered during Titan atmospheric entry. The reduced model, having fewer species and reactions than the detailed model, is better suited to coupled reacting computational fluid dynamics flowfield calculations.