碳/酚醛燃气舵热化学烧蚀过程数值研究

Numerical Research of Thermochemical Ablation about Carbon-Phenolic Jet Vane in Solid Rocket Motors

为了研究碳/酚醛燃气舵热化学烧蚀问题,在Fluent平台上采用UDF二次开发方法,对碳/酚醛燃气舵二维非定常流固热耦合过程进行了数值仿真研究。对几何建模、边界条件、热解气体逸出过程以及热化学烧蚀导致的边界退移等问题进行了详尽的描述,并选取了合适的计算模型。对不同舵偏角下燃气舵温度分布、热解气体逸出通量以及热化学烧蚀等问题进行了分析研究。结果表明:燃气舵表面化学反应以及热解气体的逸出过程能够有效降低燃气舵壁面以及内部温度,下降温度最高值约为325K;燃气舵前缘一直是热化学烧蚀最严重区域,达到0.5mm,迎风面烧蚀量次之,而背风面几乎不存在热化学烧蚀现象;迎风面热化学烧蚀会随着舵偏角的增大而变得更为严重。

To solve the problem of thermochemical ablation about carbon-phenolic jet vane,a numerical research on two-dimensional unsteady fluid-solid-thermal coupling was done using secondary development on Fluent platform by UDF. Geometric model,boundary conditions,evolution process of pyrolysis gas as well as surface retired due to thermochemical ablation were described carefully,and a suitable numerical model was selected. Temperature distribution of jet vane,mass flux of pyrolysis gas and thermochemical ablation at different deflection angles were analyzed. The results show that,thermochemical reactions on surface and evolution of pyrolysis gas can help reducing surface and interior temperature of jet vane,the highest temperature reduction is about 325 K. Leading edge is always the most serious thermochemical ablative area of jet vane at about 0.5mm followed by upwind side,however,there is almost none surface ablation on leeward side. As the deflection angle of jet vane increases,ablation of upwind side becomes much more serious.