par Helber, Bernd;Chazot, Olivier;Magin, Thierry 
;Hubin, Annick
Référence 44th AIAA Thermophysics Conference(44: 2013-06-24), American Institute of Aeronautics and Astronautics Inc
Publication Publié, 2013
;Hubin, Annick Référence 44th AIAA Thermophysics Conference(44: 2013-06-24), American Institute of Aeronautics and Astronautics Inc
Publication Publié, 2013
Publication dans des actes
| Résumé : | Ablation experiments of a carbon fiber preform and low density carbon-phenolic ablators were performed in the VKI Plasmatron at cold wall heat fluxes of qcw = 1 - 3MW=m2, focusing on the interaction of pyrolysis gases with air and nitrogen plasmas at test chamber pressures from ps = 1:5 - 20 kPa. The highly reactive boundary layer formed in front of the test sample was investigated along the stagnation line with three emission spectrometers. A high-speed camera was used to determine the spectrometer probing distances from the recessing surface. Spectrally resolved boundary layer emission revealed reactive products originating from pyrolysis gases and the ablation process (C2, CH, CN, NH and OH). The spectrometers measured the same emission intensity, for instance of the CN violet (B-X) system, in air plasma when reaching the same distance from the ablating surface, indicating a steady ablation process. Comparisons of measured CN violet emission to simulated spectra using SPECAIR revealed a deviation from thermal equilibrium for low pressure tests. |
