Modification of the DSMC method for a macroscopic chemical reaction

Considering some limitations of various macroscopic chemical reaction models including the total collision energy (TCE) and general collision energy (GCE) models, the new modification is implemented in the DSMC algorithm for numerical simulation of dissociation of the air along the stagnation line and around a typical hypersonic atmospheric blunt body, STS-2 in un-equilibrium conditions and modified model is compared with others conventional models. Since the TCE and GCE models are dependent on some experimental parameters (A and B in the Arrhenius equation for the reaction rate), also, due to the lack of accuracy of the QK model, modification version of chemical reaction models is presented as a hybrid of modified quantum kinetics (MQK) and modified collision energy (MCE) which this method is able to extract A and B parameters without need of experimental background. The accuracy of the current applied chemical model for the calculation of flow field characteristics is assessed by comparison of their results with other methods (analytical models and available experimental data). The results indicate that the modification of hybrid model with advantages of the independency of the empirical parameters gives more accurate results and provides more accurate solution compared to conventional methods without need of A and B constant experimental parameters.