Post-Test Sample Analysis of a Low Density Ablator Using Arcjet

Abstract

An existing computer code named super charring materials ablation (SCMA) is updated by implementing a coking process, in which a pyrolysis gas cokes within a char layer. The conservation equations for masses for resin, and coke, and energy are given. A coking rate equation is calculated by accounting for mass conservation of carbon deposited within a char layer. The method so upgraded is applied to the post-test sample analysis of the in-depth density profile for a low density ablator heated in an arcjet wind tunnel under one operating condition to evaluate the temperature variation of mass fraction of carbon contained in a pyrolysis gas used in the coking rate equation. The calculated result between with and without coking is compared to discuss the effect of coking on ablation behaviors.