Modifications to the Aerotherm Charring Material Thermal Response and Ablation Program (CMA) for Carbon Ablation Analysis

Modifications to the Aerotherm Charring Material Thermal Response and Ablation Program (CMA) have been made to resolve deficiencies that were identified during the Aerospace Nuclear Safety Program's Galileo-VEEGA ablation studies. The primary modifications deal with integrating the Hunter carbon oxidation subroutine with the mainstream ablation calculations in CMA. The modified program uses a surface temperature criterion to determine when to switch between the Hunter oxidation subroutine and the sublimation routines in CMA. The user has the option to explicitly define this temperature criterion, indirectly define it via a mass loss parameter, or generate it via a search routine. A related feature uses Hunter's algorithm to compute an 'ablation threshold temperature' of the material for switching between abalation and non- ablator routines. A secondary modification permits 'blowing' to attenuate the shock layer radiation to a carbon surface. Ablation; Algorithms; Carbon; Oxidation; Sublimation; Shock layer radiation; Reentry vehicles; Ablative materials; Graphite.