Thermal Analysis for Phenolic Impregnated Carbon Ablator/CV-1144-0 in Hypersonic Test Environments

Analysis of multidimensional in-depth thermal response for the phenolic impregnated carbon ablator (PICA)/CV-1144-0 material system in NASA Langley Research Center Hypersonic Materials Environmental Test System environments was performed using the 3-D Fully Implicit Ablation and Thermal (3dFIAT) code, which was enhanced to enable the simulation of multidimensional thin-coating burn-through and multistreams of pyrolysis gas flow. CV-1144-0 is a controlled volatility room-temperature vulcanized silicone oxygen protective coating. Three proposed in-depth thermal response models for CV-1144-0 were examined to assess their accuracy and understand how the coating affected PICA thermal performance. These proposed in-depth thermal response models were used to predict the in-depth temperature history for three groups of arcjet test models. Pyrometer surface temperature measurements and recessed surface data from laser scans were used as the boundary conditions in 3dFIAT in-depth response simulations. Data-parallel line relaxation was used to compute the surface heat flux and pressure distributions based on the surface geometries of pretest and posttest models. Comparisons between computations and thermocouple data are presented and discussed for each test model. The uncertainty of surface temperature and recession measurements on in-depth temperature prediction is investigated. The effect of CV-1144-0 coating thickness on the modeling of PICA in-depth thermal response is also studied.