Multicomponent mass transport in chemical vapor infiltration

The effects of multicomponent mass transport on the predictions of chemical vapor infiltration models are investigated. The dusty-gas model is used as basis for describing multicomponent transport in the pore space of the preforms. Results are presented over a broad range of conditions extending from the bulk to the Knudsen diffusion regime using the full dusty-gas model and a number of variants. These variants are obtained by simplifying the full form of the dusty-gas model and retaining or omitting the viscous flow terms. The presented results demonstrate the importance of using the complete form of the dusty-gas model in most applications and elucidate the implications of some of the simplifying assumptions that are commonly made in describing gaseous mass transport in chemical vapor infiltration.