Energetic characterization of Martian atmospheric flow in the arc-heated wind tunnel L2K using experimental and numerical methods

Abstract

This Master’s thesis focuses on the analysis of the hypersonic flow in the arc heated wind tunnel L2K at the German Aerospace Center (DLR) in Cologne. The flow field in the wind tunnel is studied numerically using the DLR’s CFD solver TAU and experimentally using invasive measurement techniques to determine the pitot pressure and heat flux on several models. The high enthalpy flow for Martian atmosphere, including mainly CO2 and N2, is studied in respect to the chemical non-equilibrium conditions. Two flow conditions have been defined as ESA’s post flight analysis for the ExoMars mission to use for code validation purposes. All experiments and simulations are performed the two flow conditions at two positions in the wind tunnel resulting in a total of four different flow configurations for the six models respectively. A sphere, a cylinder which is orientated orthogonal to the flow direction and a cylinder which is orientated in parallel are available in two sizes respectively. The findings are furthermore compared to theoretical theorems for the cold wall heat flux in the stagnation point and the shock stand-off distance. Overall the numerical and experimental results for heat flux and pitot pressure coincide, expect for one flow configuration. This is discussed in more detail in the thesis.