Effective oxidation model for light-weight carbon preform ablators

Krishnan Swaminathan-Gopalan, Kelly A. Stephani, Joseph Ferguson, Arnaud Borner, Francesco Panerai, Nagi N. Mansour

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Porous Microstructure Analysis (PuMA) software is used to perform simulations of molecular beam scattering experiments of hyperthermal atomic oxygen striking FiberForm, a carbon preform material used commonly as a precursor in thermal protection systems (TPS). The purpose of this study is to investigate the reactive interaction of fibrous carbon with atomic oxygen in a complex microstructure, which is the primary source of carbon removal at lower temperatures. The detailed micro-structure of FiberForm obtained from X-ray micro-tomography is used in the PuMA simulations to capture the complexity of the porous and fibrous characteristic of FiberForm. A finite-rate surface chemistry model recently constructed from the molecular beam scattering experiments on vitreous carbon is applied to each fiber of the FiberForm material. This model consists of detailed surface reaction mechanisms such as adsorption, desorption, and several types of Langmuir-Hinshelwood (LH) reactions to characterize the oxygen-carbon interactions at the surface. Comparison between the experimental and PuMA time-of-flight (TOF) distributions of both O and CO show good agreement. It wis also found that a significantly higher amount of CO is generated when the beam interacted with FiberForm, when compared with vitreous carbon. This is postulated to be primarily a result of multiple collisions of oxygen with the fibers, resulting in an higher effective rate of CO production. Multiple collisions with the different fibers, resulting from the porous nature of FiberForm is also found to thermalize the O atoms, in addition to the adsorption/desorption process. The effect of micro-structure is concluded to be crucial in determining the final composition and energy distributions of the products. Thus, an effective model for the oxygen interaction with FiberForm, fully accounting for the detailed micro-structure, for use in Computational Fluid Dynamics (CFD) and material response codes, is presented.

Original languageEnglish (US)
Title of host publicationAIAA Scitech 2019 Forum
PublisherAmerican Institute of Aeronautics and Astronautics Inc, AIAA
ISBN (Print)9781624105784
StatePublished - 2019
EventAIAA Scitech Forum, 2019 - San Diego, United States
Duration: Jan 7 2019Jan 11 2019

Publication series

NameAIAA Scitech 2019 Forum


ConferenceAIAA Scitech Forum, 2019
Country/TerritoryUnited States
CitySan Diego

ASJC Scopus subject areas

  • Aerospace Engineering


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