碳/酚醛复合材料体积烧蚀行为的数值模拟

Numerical simulation of volume ablation behavior of carbon/phenolic composite

为了准确掌握碳/酚醛防热复合材料的烧蚀特性和烧蚀机理,基于质量和能量守恒、材料热分解以及物性的计算方程,应用数值模拟方法计算了碳/酚醛复合材料的热响应和体积烧蚀行为.计算结果表明：烧蚀过程中碳/酚醛复合材料具有不均匀的温度场分布,在厚度方向上最大温差达到了634 K,并且加热面上基体温度比纤维温度高出了175 K;酚醛基体的平均密度几乎呈线性衰减,40 s时平均密度降低了37.8%;烧蚀过程中酚醛基体具有较大的质量损失,40 s时质量损失了0.31 g,是20 s时的2.4倍.

In order to accurately grasp the ablation behavior and ablative mechanism of the carbon/phenolic composite,a mathematical model was proposed based on the energy-and mass-conservation principles,the thermal decomposition of materials as well as the calculation of thermophysical properties.The thermal response and volume ablation behavior of the carbon/phenolic composite was simulated.The calculated results show that the carbon/phenolic composite has an uneven temperature distribution.The maximum temperature difference in the thickness direction reaches 634 K,and the matrix temperature on the heating surface is 175 K higher than the fiber temperature.The average density of the phenolic matrix is almost linearly attenuated and the average density is reduced by 37.8% at 40 s.The phenolic matrix has a significant mass loss during ablation.The mass loss is 0.31 g at 40 s, which is 2.4 times the mass loss at 20 s.