A Brownian motion technique to simulate gasification and its application to C/C composite ablation

Jean Lachaud (1) , Gerard L. Vignoles (1)

1 LCTS - Laboratoire des Composites Thermostructuraux

Ablation of carbon-carbon composites (C/C) results in a heterogeneous surface recession mainly due to some gasification processes (oxidation, sublimation) possibly coupled to bulk mass transfer. In order to simulate and analyse the material/environment interactions during ablation, a Brownian motion simulation method featuring special Random Walk rules close to the wall has been implemented to efficiently simulate mass transfer in the low Péclet number regime. A sticking probability law adapted to this kind of Random Walk has been obtained for first-order heterogeneous reactions. In order to simulate the onset of surface roughness, the interface recession is simultaneously handled in 3D using a Simplified Marching Cube discretization. This tool is validated by comparison to analytical models. Then, its ability to provide reliable and accurate solutions of ablation phenomena in 3D is illustrated.

Mots clés: Brownian motion; Sticking event; Receding surfaces; Carbon–carbon composites

Domaines: Matériaux; Matériaux

Jean Lachaud, Gerard L. Vignoles. A Brownian motion technique to simulate gasification and its application to C/C composite ablation. Computational Materials Science, 2008, 44 (4), pp.1034-1041. ⟨10.1016/j.commatsci.2008.07.015⟩. ⟨hal-00410192⟩