Rarefaction effects in NASA arc jet testing at SCIROCCO facility

In the frame of numerical rebuilding of SCIROCCO Plasma Wind Tunnel measurements, made during a facility characterization test campaign performed for NASA at increasing enthalpy and constant pressure, an important gap among measured and numerically predicted values of heat flux led to deep analyses of the models usually employed for test rebuilding. The Navier-Stokes model with chemical reacting non-equilibrium reactions, denoted a lack of physical accuracy due to local rarefaction effects, as certified by means of the continuum breakdown parameter. Then, a set of direct simulation Monte Carlo was performed to reduce the gap with the measured heat fluxes, and understand the real test chamber environment that was surrounding the probe. Finally, the numerical and experimental results, was related in terms of Knudsen number and coefficient of heat flux, to numerical and experimental results available in literature.