HYPERSONIC RAREFIED FLOWS DSMC ANALYSIS BY A SIMPLIFIED CHEMICAL MODEL

摘要

A simplified model for the analysis of molecular and reaction dynamics in hypersonic flows of rarefied gases is used to investigate the influence of oxygen dissociation in the prediction of aerothermal coefficients. The model is a direct simulation Monte Carlo method derived from the Larsen-Borgnakke method for the analysis of inelastic collisions. Tests performed in conditions near to re-entry conditions at an altitude of 115 km show significant effects of chemical reactions on the evaluation of the heat-transfer coefficient, while no real influence is found on lift and drag coefficients. Good agreement is found with results achieved using more sophisticated chemical models, as a 4 % maximum difference arises in the determination of surface quantities in re-entry conditions at 160 km. [References: 12]