Finite-rate and equilibrium study of graphite ablation under arc-jet conditions

Aleksander L. Zibitsker, Joel A. McQuaid, Eric C. Stern, Grant E. Palmer, Benjamin J. Libben, Christoph Brehm, Alexandre Martin

Research output: Contribution to journalArticlepeer-review

3 Scopus citations

Abstract

Arc-jet facilities play a primary role in recreating aerothermal conditions experienced by atmospheric entry vehicles and are widely used to test the performance of thermal protection materials. In this work, we utilize a developed coupled framework between an overset flow solver CHAMPS NBS-Cart, and a material solver KATS-MR to study the ablation of graphite under arc-jet conditions. We implement a 12-species gas phase model to accurately represent the air-carbon mixture, including argon species present in the flow. The gas phase is modeled with a two-temperature thermo-chemical non-equilibrium model without considering electronic and ionization effects. The gas-surface interactions are modeled with a newly developed air-carbon ablation model accounting for oxidation, nitridation, and recombination reactions. In addition, the model is augmented with carbon sublimation reactions experienced at high heating conditions. The chemical state at the surface is tightly coupled with the flow solver, resulting in the improved accuracy and effectiveness of the simulation. The coupled approach is applied to study two experimental test cases conducted at the IHF arc-jet facility at NASA Ames. The predicted results are validated against measured recession, surface, and in-depth temperatures and compared to the prediction of the uncoupled, equilibrium-based approach. Finally, the accuracy of the prediction is explored with respect to the environmental properties, such as the diffusion coefficient, and material thermal conductivity.

Original languageEnglish
Article number106069
JournalComputers and Fluids
Volume267
DOIs
StatePublished - Dec 15 2023

Bibliographical note

Publisher Copyright:
© 2023 Elsevier Ltd

Keywords

  • Arc-jet flow
  • Coupled simulation
  • Graphite ablation
  • Material response
  • Overset grid solver

ASJC Scopus subject areas

  • General Computer Science
  • General Engineering

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