Analytical modeling of the steady state ablation of a 3D C/C composite

Following an analysis of surface roughness features that develop on a 3D C/C composite during abla-tion, i.e. wall recession by oxidation and/or sublimation, a modeling strategy is set up in order to predict the composite behavior from that of its components. It relies on two changes of scale: (i) microscopic scale (fiber, matrix) to mesoscopic scale (bundle) and (ii) mesoscopic scale (bundle, matrix) to macro-scopic scale (composite). The physical basis is a general model for receding surfaces under a gasification process coupled to mass transfer. At each scale, the 3D surface equation is analytically solved in steady state considering a 1D mass transfer perpendicular to the overall surface. The models are validated by comparison to experimental data. Key words: Carbon-carbon composites, ablation, moving interface, changes of scale, phenomenological model