Tim Roos , Adrian Pudsey , Tobias Sander , Javier Garcia-Garrido , Christian Mundt , Mathew Bricalli
DOI Number XXX-YYY-ZZZ
Conference Number HiSST 2018_41101143
Recent interest in missions to Mars brings about the necessity for ground based testing of the flows experienced during entry into the Martian atmosphere. Located at the Bundeswehr University in Munich is an arc-heated plasma wind tunnel that can provide steady-state, high-enthalpy CO2 flows at realistic entry conditions into Martian atmosphere. Previous experimental work using two-photon laser-induced fluorescence (LIF) excitation spectra of carbon monoxide provides temperature profiles of the nozzle flow from the plasma wind tunnel, enabling the validation of numerical modelling approaches to this nozzle flow. The objective of this study is to improve the numerical prediction of the Bundeswehr university’s plasma wind tunnel by considering the effect of adding N2 to the flow as a diluent. Four N2 dilution ratios were considered at stagnation enthalpies of 16 MJ/kg and 19 MJ/kg (including the enthalpy of formation of CO2). At higher stagnation enthalpy the N2 mass fraction was found to increase nozzle flow temperature by up to 13%, while the effect of N2 only had a slight effect at the highest dilution ratio for the low-enthalpy case. The CO mass fraction was found to be affected less in the high-enthalpy case than in the low-enthalpy case, expected to be due to dissociation of CO in the nozzle. For the mixture representing Martian atmosphere the hot core flow was found to be slightly smaller in the high-enthalpy case, however the general shape of the jet was very similar. The results of the present study provide a good basis for numerical validation with future experimental results.