烧蚀花纹的分形结构及菱形花纹传热特性

Fractal Character of Ablation Cross-Hatching and Heat Flux Measurement on DiamondD-Carved Plate

在外流Ｍ＝５湍流边界层状态下，模型为１７０×３００ｍｍ￣２蜂蜡平板上进行了烧蚀花纹图案生成的实验研究，通过实验证明了人工安置干扰源并不影响烧蚀材料表面花纹的有序结构，对大面积烧蚀花纹的分析表明，局部花纹结构具有随机性质，因此烧蚀花纹具有分形结构的特性，用分形方法可以大致模拟花纹生成图案。菱形沟槽热流测量结果表明，在材料有烧蚀响应的情况下，大面积菱形花纹具有稳定性质，不产生局部烧蚀崩溃现象。

An experiment on forming of cross-hatch on the ablation material surface has been done under the condition of Mach 5 and tur-bulent boundary layer regime.Artifitial disturbances created by randomly setting several pins along a line perpendiculer to the flow direction have shown stochastical character of local cross-hatch and independence of global orderly structure,therefore the pattern appeared fractal behavior.A fractal structure has been given in the paper.In order to verifv the existance of cross-hatch structure for ablating materials a heat flux measurement has been performed on a metallic plate of l70 × 300mm￣2,on which was carved a series of diamond grooves.The distribution of heat flux has shown that an equilibrium regime existed with a respective cross-hatch structure.