Simulation of radiating CO2-N2 shock layer experiments at hyperbolic entry conditions

Numerical simulations supporting radiating shock layer experiments with a CO2 – N2 test gas in the X2 free-piston impulse facility are presented. A ueq = 9.7 km/s, 1L = 5.4×10−5 kg/m2 expansion tunnel condition and a u1 = 8.5 km/s, 1 = 2.35×10−4 kg/m3 shock tube condition are investigated. Shock layer simulations with the Euler equations, a two-temperature thermal model and coupled nonequilibrium radiation are compared with radiant intensity and temperature profiles derived from emission spectroscopy measurements of the CN Violet band system. Applying the CO2 – N2 reaction scheme modifications proposed by Lee, Park and Chang1 and omitting translation-electron energy exchange is found to give the closest agreement with calibrated intensity measurements.

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