A Volume Averaged Model for Heterogeneous Chemical Reactions in Zirconium Carbide High Temperature Ceramics

During atmospheric re-entry applications, thermal protection systems (TPS) are not only submitted to high thermal and mechanical stresses, but also to a variety of highly reactive chemical species inside the boundary layer that can trigger heterogeneous reactions with the protection components. For carbon fibers based material, the depletion of carbon atoms by oxygen molecules induces high ablation rates of the protection system, that in turn reduce material performances. To protect the fibers from hostile environments, composite materials have been introduced, in particular composite ceramics, which have the advantage to present good thermal and mechanical properties for hypersonics applications. In this study, a mathematical model for the oxidation of this class of material is presented and implemented within the Porous material Analysis Toolbox based on OpenFOAM (PATO) framework to evaluate the protective role of the matrix phase under oxidation, and the ceramics composite response under a variety of external environments.