Examination of ultraviolet radiation theory for bow shock rocket experiments

Comparison is made between the results from a modified state-of-the-art radiation code and bow shock radiation data from recent flight experiments. Initial predictions of the radiation did not yield satisfactory comparison with the first flight experiment, flown at 3.5 km/sec between altitudes of 40 and 70km, despite improvements to the original flow model. It is found that characterizing the NO excited state population with the translational temperature, rather than the vibrational temperature, yields better comparison to the flight data. Comparison of bow shock data from the second flight, flown at 5.1 km/sec at altitudes of 70 to 90 km, shows that modifications in either flow or radiation modeling are still needed, particularly at high altitudes. The quasi-steady-state distribution of electronic states of NO is found to be valid for these flows.