防热材料起泡现象的物理建模和计算方法研究

一些烧蚀试验发现特定配方的有机涂层防热材料在受到加热时,在有机物热解时除产生通常的炭化层外,在热解区附近还会出现较严重的起泡物理现象,在防热层内部区域形成很明显的较大泡沫,使防热层厚度增加,改变了防热材料的传热性能和物理模型,减缓了热量向内部结构的传递,降低内部结构的温升,对防热结构设计非常有利.本文细致分析了外部加热时有机涂层的热解烧蚀过程,初步建立防热材料起泡现象的物理模型和控制方程,数值模拟了起泡现象对内部温度场结果的具体影响,并与试验结果进行了比较.

PHYSIC MODEL AND COMPUTATION ON BUBBLE PHENOMENON OF THERMAL PROTECTION STRUCTURE

At present, the phenomenon of bubble sometimes may appears in pyrolysis field via obser- vation of the ablation experiments, which makes the thickness of the thermal protection layer increase significantly. The size of the bubble not only relates to the physical properties, but also relates to the exterior heat rate, exterior pressure, internal pressure and temperature gradient etc. The phenomenon of bubble changes the diathermancy and physical model, and decelerates the transfer of the tempera- ture to the...