Wall Catalytic Effects on Aerodynamics of the Mars Entry Capsule

Accurate prediction on the hypersonic aerodynamics during the Mars entry period is of great importance. In this study, the chemical non-equilibrium method is utilized to numerically investigate the effects of wall catalytic performance on the aerodynamic characteristics of the Mars entry capsule named Mars Science Laboratory (MSL). Two typical catalytic wall conditions (Super-catalytic and Non-catalytic) are chosen to take account of the catalytic effects, respectively. Numerical results show that wall catalytic condition have ignorable effect on the capsule's pressure. The shear stress predicted by the super-catalytic wall condition are overall higher than that by the non-catalytic wall, with the maximum discrepancy of up to 21% at the nose and shoulder of forebody. The maximum relative discrepancies of axial force coefficient, normal force coefficient and pitch moment coefficient predicted by different catalytic wall conditions are merely 0.3%, 1.2% and 1.3%, respectively, indicating the minimal effect of wall catalytic properties on aerodynamic force coefficients for large blunt body shapes such as the Mars entry capsule.