DSMC Simulation of Entry Vehicle Flowfields Using a Collision‐Based Chemical Kinetics Approach

A study of high‐altitude, nonequilibrium flows about an Orion Command Module (CM) is conducted using the collision‐based chemical kinetics approach introduced by Bird in 2008. DSMC simulations are performed for Earth entry flow conditions and show significant differences in molecular dissociation in the shock layer from those obtained using traditional temperature‐based procedures with an attendant reduction in the surface heat flux. Reaction rates derived from equilibrium simulations are also presented for selected reactions relevant to entry flow kinetics, and comparisons to various experimental and theoretical results are presented.