Transient solution of chemical vapor infiltration/deposition in a reactor Original Research Article

A chemical vapor infiltration/deposition (CVI/CVD) reactor used to manufacture carbon/carbon (C/C) composites aircraft brakes has been simulated numerically. This simulation accounts for a homogeneous gas reaction mechanism as well as a heterogeneous surface reaction mechanism that is coupled with hydrogen inhibition effect and a pore model. Non-Boussinesq (low Mach number) equations are used to predict fluid flow, heat transfer, and species concentrations inside the reactor and within the porous brakes. In addition, we use an efficient quasi-steady state integration procedure to predict porosity distribution at different infiltration times. Results showing the flow, temperature and concentration fields, as well as the deposition rate of the pyrolytic carbon and porosity change with time, are presented. Optimized operating conditions for pressure and temperature are obtained through a parametric study that consists of 16 different cases. Recommendations are presented for improving performance.