Simulation of Carbon-Carbon Crack Growth Due to Carbon Oxidation at High Temperatures

摘要

High-temperature gas-dynamic computational techniques are employed to study microflows in expanding crack channels caused by the oxidation of the channel carbon walls. Wall regression rates for three reinforced carbon-carbon samples that were tested in a high-enthalpy arcjet environment were modeled. The test geometries and flow conditions span flow regimes from the transitional through the continuum, but the same mechanism for wall material loss, atomic oxygen reaction with bare carbon, was used in all three cases. Kinetic (direct simulation Monte Carlo) and continuum (Navier-Stokes) gas-dynamic approaches were used. The predicted wall regression rates were found to agree with arcjet measurements, and the general specimen shape change was predicted. Local gas flowfield results were found to affect the oxidation rate in a manner that cannot be predicted by previous mass loss correlations. The method holds promise for future modeling of materials gas-dynamic interactions for hypersonic flight.