Effect of internal energy excitation on supersonic air flow

The effect of upstream vibrational energy excitation on supersonic blunt-body drag is studied using computational fluid dynamics. The simulations model two sets of experiments where a discharge excites the air upstream of a sphere. It is assumed that the discharge weakly dissociates the oxygen and excites the vibrational energy of the diatomics. The computations show that the bow shock standoff distance increases, and the drag on the sphere is found to decrease by as much as 26%. The results are in general agreement with the experiments, indicating that vibrational energy excitation may explain the observed behavior.