Experimental and numerical simulation, by an arc-jet facility, of hypersonic flow in Titan's atmosphere

This paper summarizes experimental and numerical results on high enthalpy hypersonic flows in nitrogen–methane mixtures. The experimental results have been obtained by the Small Planetary Entry Simulator (SPES), an arc-jet hypersonic wind tunnel in operation at the University of Naples “Federico II”. The facility has been used in the past to simulate entry conditions into Earth’s and Mars’ atmosphere and has recently been upgraded to simulate entry into Titan’s atmosphere. Numerical simulations of the flow field in the facility, for a nitrogen–methane mixture in chemical nonequilibrium have been performed. The chemical species and the heat flux distributions on a calorimeter located in the arc-jet test chamber have been computed. The ability to perform a numerical rebuilding of the facility, by comparing numerical and experimental results has been investigated. The paper also highlights the importance of the wall catalyticity for the characterization of the thermal response of materials in high enthalpy flow.