Robust Numerical Simulation of Porosity Evolution in Chemical Vapor Infiltration I: Two Space Dimension

A numerical method is presented for describing pore structure evolution during chemical vapor infiltration densification and other physical problems of gas–solid reactions involving growth of a porous solid. Our method, based on the model proposed in (Jin et al., 1997, J. Mater. Res. 14, 3829), uses the level set equation of Eulerian formulation coupled with a boundary value problem of the Laplace equation. It allows robust numerical capturing of topological changes such as merging and formation of pores during the process. An efficient numerical method for the detection of the inaccessible pores is introduced for models in the kinetic limit, where the front speed is constant. Numerical examples show that this model will accurately predict not only the residual porosity, but also the precise close-off time, location, and shape of all pores.