Gas–surface interactions in lightweight fibrous carbon materials

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

Research output: Contribution to journalArticlepeer-review

Abstract

We investigate reactive and non-reactive scattering of hyperthermal beam of gas particles within highly porous carbon-fiber preform using particle-based numerical simulations. High-resolution X-ray tomography images of the microstructure is used to resolve its complex fiber network. The gas–surface interaction is studied at material temperatures up to 2000 K, typical of hypersonic aero-thermal environments. We extended a detailed surface chemistry model for oxidation of vitreous carbon to carbon-fiber materials. The model agrees well with experiments and predicts increasing oxidation product flux with larger porosities. Higher porosities lead to a larger fraction of thermalized argon atoms and greater mole fraction of CO for the oxygen beam due to greater penetration of the beam into the microstructure. It is found that a 6% porosity increase results in higher mole fractions of CO and lower amounts of O, with differences of around 10% of the total product flux. Furthermore, we construct an effective oxidation model with porosity-dependent rates that inherently accounts for the characteristics of the material microstructure and its varying porosity. Comparison of full microstructure simulation results and the effective model applied to a flat surface showed excellent agreement, thus suggesting that the model can be used directly in computational fluid dynamics codes.

Original languageEnglish (US)
Article number111190
JournalComputational Materials Science
Volume205
DOIs
StatePublished - Apr 1 2022

Keywords

  • Ablation
  • Carbon fibers
  • Gas–surface interaction
  • Oxidation
  • Tomography

ASJC Scopus subject areas

  • General Computer Science
  • General Chemistry
  • General Materials Science
  • Mechanics of Materials
  • General Physics and Astronomy
  • Computational Mathematics

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