Two-Dimensional Implicit Thermal Response and Ablation Program for Charring Materials

The TITANprogramforpredicting charringmaterial ablationand shapechangeof thermal protectionmaterials is presented. The governing equations include energy conservation and a three-component decomposition model. The surface energy balance condition is solved with a moving grid to calculate the shape change due to surface recession. The governing equations are discretized with a Ž nite volume approximation with a general body-Ž tted coordinate system. A time-accurate solution is achieved by an implicit time-marching techniquewith Gauss–Seidel line relaxationwith alternating sweeps. Benchmark solutionsare calculated and comparedwith availablesolutions to check code consistency and accuracy. For fully coupled solid– uid simulation, this technique has been directly integrated with both a high-Ž delity Navier–Stokes solver and an aerothermal  owŽ eld engineering correlation code. Representative computations, including a slender hypersonic reentry vehicle and a  at-faced cylinder model in an arcjet test, are presented and discussed in detail.