Experimental and numerical studies of ionizing flow in a super-orbital expansion tube

Comparisons are made between experimental measurements and numerical simulations of ionizing flows generated in a super-orbital facility. Nitrogen, with a free-stream velocity of around 10 km/s, was passed over a cylindrical model and images were recorded using two-wavelength holographic interferometry. The resulting density, electron concentration and temperature maps were compared with numerical simulations by the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA). The results showed generally good agreement in shock location and density distributions. Some discrepancies were observed for the electron concentration, possibly due to the finite length of the cylinder used in the experiments.