par Helber, Bernd;Turchi, Alessandro;Chazot, Olivier;Magin, Thierry 
;Hubin, Annick
Référence 11th AIAA/ASME Joint Thermophysics and Heat Transfer Conference(11: 2014-06-16), American Institute of Aeronautics and Astronautics Inc.
Publication Publié, 2014
;Hubin, Annick Référence 11th AIAA/ASME Joint Thermophysics and Heat Transfer Conference(11: 2014-06-16), American Institute of Aeronautics and Astronautics Inc.
Publication Publié, 2014
Publication dans des actes
| Résumé : | Ablation experiments have been carried out with the carbon-phenolic material AQ61 and a non-pyrolyzing carbon fiber preform in sub- and supersonic air and nitrogen plasmas in the VKI Plasmatron facility. We performed an in-situ recession analysis, including volumetric ablation, and observed the temperature and radiance of the surface for emissivity estimations, as well as spatial molecular radiation profiles in the boundary layer, which were compared to a numerical approach. Surface temperatures as low as 1600K allowed observation of the temperature distribution over the surface using an infrared camera. The carbon preform test samples were varied in shape as well as regarding their fiber direction. Sublimation of the surface was reached in supersonic plasma flow at a cold wall heat flux of 9:5MW/m2. Carbon preform emissivities were found to be in the order of 0.86 - 0.97. A stagnation line description with an ablation boundary condition helped to reproduce experimentally measured boundary layer emission profiles of the CN violet molecule. In spite of the very simplified model, emission intensities were in the same order of magnitude compared to the experimental data. The model was able to reconstruct the location of the maximum emission for two cases. The char layer was examined by Scanning Electron Microscopy, illustrating degradation after nitrogen ablation. |
