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Reentry space vehicles face extreme conditions of heat §ux when interacting with the atmosphere at hypersonic velocities. Stagnation point heat §ux is normally used as a reference for Thermal Protection Material (TPS) design; however, many critical phenomena also occur at o¨-stagnation point. This paper adresses the implementation of an o¨-stagnation point methodology able to duplicate in ground facility the hypersonic boundary layer over a §at plate model. The ¦rst analysis using two-dimensional (2D) computational §uid dynamics (CFD) simulations is carried out to understand the limitations of this methodology when applying it in plasma wind tunnel. The results from the testing campaign at VKI Plasmatron are also presented.

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Spacecrafts re-entering the atmosphere at hypersonic regimes consider the wall catalytic activity on their design phase. Therefore, accurate catalytic models are required to maximize mission efficiency. In order to develope and validate an experimental approach for a catalytic model in the VKI-Plasmatron facility, a good enthalpy characterization of the freestream plasma flow is required. A method to rebuild the boundary layer outer edge properties based on calorimetric measurements is described and consolidated in this paper. The technique requires the prior determination of the wall catalytic conditions on a reference material (γ ref ), so a method called Mini-Max is applied under different facility conditions and a reference catalysis onCu of γ ref = 0.0265 ± 26.42% at 50mbar and γ ref = 0.0156 ± 40.81% at 100mbar is obtained. Additional tests in different probe geometries suggest that the boundary layer characteristics affect the determination of the recombination coefficient, which is important for the future development of flight extrapolation techniques of wall boundary conditions.