Examination of theory for bow shock ultraviolet rocket experiments - II

In this article the radiation model, NEQAIR, used to calculate the mid-uv radiance for Bow Shock 1 and 2 flight conditions, is examined in detail. An approximate equation for the upper state NO population is derived that explains the density dependence of the calculations and sensitivity to changes in specific rates. Estimated neutral collisional excitation rates are replaced with rates based on experiment. For conditions corresponding to the two flights, the radiation obtained with an explicit treatment of the electronic excitation process was similar to that obtained from the original model. For the first time, we also test the validity of the quasi-steady-state assumption in these rarefied flows. We find that the quasi-steady-state distribution of electronic states of NO is valid for these flow conditions.