P. Jorge, D. Henneaux, A. Turchi, T. Magin
DOI Number XXX-YYY-ZZZ
Conference Number HiSST-2022-310
During space debris atmospheric reentry, one of the important physical phenomena arising for metallic
components is the formation of an oxide layer on the surface exposed to the high-enthalpy flow. Due
to the change in material properties, the debris thermal behavior will be modified, e.g. the changes in
emissivity and conductivity will affect the heat transfer by radiation and conduction, respectively. This
work presents numerical tools developed to quantify and evaluate the importance of oxidation on the
heat transfer mechanisms of reentering metallic debris. To achieve this, the oxide mass and thickness
gains of Invar-36 oxidized in air plasma are numerically simulated in a 1-D finite difference framework.
Moreover, a fully coupled mass-heat equation system is implemented allowing investigations of the thermal
behavior of reentering oxidizing materials. The analysis is focused both on the surface effects of oxidation
(emissivity change, heat of oxidation reactions) and in-depth effects caused by the changes in material
properties (thermal diffusivity). CFD simulations are performed to retrieve the Stanton number and
obtain explicitly the convective heat flux-wall temperature dependency. The influence of oxidation on
the debris temperature is studied with six test cases representing full oxidation modelling, modelling of
the emissivity changes, and no oxidation modeling at different flow conditions. Based on this analysis,
neglecting oxidation induces an over-prediction of the material ablation and that in-depth modeling is
necessary depending on the particular boundary conditions of the problem.