Development and Verification of a One-Dimensional Ablation Code Including Pyrolysis Gas Flow

The development and verification of a one-dimensional material thermal response code with ablation is presented. The implicit time integrator, control volume finite element spatial discretization, and Newton's method for nonlinear iteration on the entire system of residual equations have been implemented and verified for the thermochemical ablation of internally decomposing materials. The study covers decomposing materials including decomposition kinetics, pyrolysis gas flow through the porous char layer, and a mixture (solid and gas) energy equation. A verification problem intended to examine the implementation of the math model is presented for the thermochemical ablation of a carbon-phenolic ablator that exercises every term in the system of governing equations.