比例(比率)
烧蚀
计算机科学
材料科学
工程类
航空航天工程
地图学
地理
作者
Jean Lachaud,Nagi N. Mansour
出处
期刊:48th AIAA Aerospace Sciences Meeting Including the New Horizons Forum and Aerospace Exposition
日期:2010-01-04
被引量:26
摘要
This slide presentation reviews the ablation by oxidation of carbon-fiber preforms impregnated in carbonized phenolic-formaldehyde matrix is modeled at microscopic scale. Direct numerical simulations show that the matrix ablates in volume leaving the carbon fibers exposed. This is due to the fact that the reactivity of carbonized phenolics is higher than the reactivity of carbon fibers. After the matrix is depleted, the fibers ablate showing progressive reduction of their diameter. The overall material recession occurs when the fibers are consumed. Two materials with the same carbon-fiber preform, density and chemical composition, but with different matrix distributions are studied. These studies show that at moderate temperatures (< 1000K) the microstructure of the material influences its recession rate; a fact that is not captured by current models that are based on chemical composition only. Surprisingly, the response of these impregnated-fiber materials is weakly dependent on the microstructure at very high temperatures (e.g., Stardust peak heating conditions: 3360K).
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