Measurement and analysis of nitric oxide radiation in an arc-jet flow

摘要: Radiation from the nitric oxide (NO) band systems emitted by flow in test section of a 20-MW arcjet wind tunnel was measured and compared with computed values for purpose testing validity an existing thermochemical model. The settling chamber pressure enthalpy were 2.4 atm 28 ± 10 MJ/ kg, respectively. measurements made using photographic films wavelength region 225 to 305 nm. Of four NO (beta, gamma, delta, epsilon), vibrational transitions observed only upper v' = 0 levels. Excitation temperatures deduced comparing experimental spectrum those calculated nonequilibrium radiation code NEQAIR. rotational, vibrational, electronic excitation data Tr 560 50 K, Tv < 950 rex 11,500 520 A multitemperature nozzle NOZNT used calculate flow. — electron thermal temperature Te 6100 respectively at 30 MJ/kg. presented results show that centerline value heat transfer measurement code, one can predict freestream conditions wind-tunnel fairly well. Nomenclature cross-sectional area nozzle, m2 H enthalpy, MJ/kg / intensity spectral line, W/(cm2-ju,-sr) T heavy particle translational temperature, K Tex rotational v quantum number x distance throat, m Subscripts mass averaged species index