含碱金属杂质的高超声速烧蚀流场特性数值模拟

针对高超声速飞行器的烧蚀现象,采用Newton迭代的空间推进方法,数值求解化学非平衡的抛物化Navier-Stokes(PNS)方程.以黏胶基碳布-氨酚醛树脂为烧蚀材料,建立了含碱金属杂质的18组分33反应的化学反应模型,计算了小钝锥体的壁面温度,并和现有文献结果进行对比验证.在此基础上,对含碱金属杂质的高超声速烧蚀流场进行了模拟,深入分析了含碱金属杂质的烧蚀反应对流场温度、压力和电子数密度的影响.结果表明:烧蚀反应使得流场温度较非烧蚀情况增加了10%~15%;考虑碱金属杂质Na后,流场电子数密度增大了1~2个数量级.

Numerical simulation of characteristic of hypersonic ablation flow field containing alkali-metal impurities

As for the ablation of hypersonic vehicles,the parabolized Navier-Stokes(PNS) equations of chemical non-equilibrium were calculated numerically based on a kind of Newton-type iteration method.The chemical model of 18 species 33 reactions containing alkali-metal impurities was established on the basis of a carbon-phenolic ablative material.Firstly,the wall temperature of small blunt cone was computed and the numerical results were validated by comparing with those in a reference.Then,the hypersonic ablation flow field containing alkali-metal impurities were simulated and the effects of ablation reactions on the flow parameters were deeply analyzed.The results show that compared with non-ablation condition,the temperature of flow field increases by 10% to 15% in ablation reactions.And the electron number densities increase by 1 to 2 orders of magnitude after taking alkali-metal Na into consideration.