表面缺陷对原子氧掏蚀效应影响的数值模拟研究

Kapton作为基底的热控涂层被广泛应用于航天器的外表层设计中,表面保护层中缺陷处所发生的掏蚀效应是近地轨道空间飞行时原子氧对此类热控材料作用的一种主要方式。文章通过蒙特卡洛方法研究了这些尺寸参数与原子氧效应之间的关系。结果表明,保护层缺陷的宽度直接影响进入缺陷内的原子氧的数量,空腔的“颈部”宽度与空腔最大宽度之比随着缺陷宽度增加,掏蚀深度的增加速度则随着缺陷的加宽而变小;保护层厚度主要对初次入射原子氧的入射过程有影响,加厚保护层可以减小原子氧的掏蚀深度和掏蚀空腔的宽度。这些结果可为原子氧防护层的设计提供参考依据。

Numerical Simulation of the Influences of Defect Size in the Protective Coatings on the Atomic Oxygen Undercutting

Kapton is frequently used as the base of thermal control materials on the surface of spacecrafts. Atomic oxygen undercutting at defect sites in the coating is a normal threat to these protective coated Kapton in LEO space flight. In this paper, Monte Carlo method is used to determine the dependence of atomic oxygen undercutting erosion upon defect size. Results indicate that the configuration of atomic oxygen undercut cavity is different with different defect sizes. The wider defect has a more flat undercut cavity, which is wider at the bottom than at the top. The width of the atomic oxygen undercut cavity varies with the thickness of the protective coatings, and the depth of undercut cavity also sees a small change. In summary, the numerical simulation results can provide a useful guide to develop new materials and protective coatings for aerospace applications.