Recent molecular beam experiments of high velocity O, N, and O2 impacting carbon material at high temperature produced detailed surface chemistry data relevant for carbon ablation processes. New data on O and N reactions with carbon has been published using a continuous molecular beam with lower velocity (2000 m/s) and approximately 500 times higher beam flux than previous pulsed-beam experiments. This data is interpreted to construct a new air-carbon ablation model for use in modeling carbon heat shield ablation. The new model comprises 20 reaction mechanisms describing reactions between impinging O, N, and O2 species with carbon and producing scattered products including desorbed O and N, O2 and N2 formed by surface-catalyzed recombination, as well as CO, CO2, and CN. The new model includes surface-coverage dependent reactions and exhibits non-Arrhenius reaction probability in agreement with experimental observations. All reaction mechanisms and rate coefficients are described in detail and each is supported by experimental evidence or theory. The model predicts pressure effects and is tested for a wide range of temperatures and pressures relevant to hypersonic flight. Model results are shown to agree well with available data and are shown to have significant differences compared to other models from the literature.
|Original language||English (US)|
|Title of host publication||AIAA Scitech 2021 Forum|
|Publisher||American Institute of Aeronautics and Astronautics Inc, AIAA|
|Number of pages||24|
|State||Published - 2021|
|Event||AIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2021 - Virtual, Online|
Duration: Jan 11 2021 → Jan 15 2021
|Name||AIAA Scitech 2021 Forum|
|Conference||AIAA Science and Technology Forum and Exposition, AIAA SciTech Forum 2021|
|Period||1/11/21 → 1/15/21|
Bibliographical noteFunding Information:
This work was sponsored by the U.S. Air Force Office of Scientific Research (AFOSR) under grant FA9550-17-1-0057. The views and conclusions contained herein are those of the authors and should not be interpreted as necessarily representing the official policies or endorsements, either expressed or implied, of the AFOSR or the U.S. Government.
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