固冲发动机补燃室氧化铝凝固过程研究

基于经典形核理论,研究了氧化铝液滴冷却凝固过程中液滴温度以及固相体积分数等参数的变化,计算了不同条件下液滴形核、再辉等阶段的凝固速率。在此基础上,对固体火箭冲压发动机补燃室内的氧化铝凝固过程进行了分析。研究表明:液滴初始粒径和环境温度对凝固速率影响很大,环境温度越高,液滴凝固越慢。在补燃室环境中,氧化铝所处的区域不同,其形态也不尽相同。在补燃室头部掺混区,氧化铝主要是以液态或固液混合态存在,固相体积分数较小;在低温区域,氧化铝主要是以固态或固液混合态存在,固相体积分数较大。

Study of Al2O3 Solidification Process in the Secondary Combustion Chamber of Solid Rocket Ramjet

Based on classical nucleation theory, temperature and solid volume fraction of Al₂O₃ droplet during solidification are investigated. The solidification rate under different conditions during nucleation and recalescence is calculated. On the basis of the above discussion, the solidification process of Al₂O₃ droplet in the secondary combustion chamber of solid rocket ramjet is analyzed. The result shows that initial particle size and ambient temperature have a great effect on solidification rate. The higher the ambient temperature is, the more slowly the droplet solidifies. We also find that Al₂O₃ has different states at different regions in the secondary combustion chamber of solid rocket ramjet. The state of Al₂O₃ is mostly liquid or solid-liquid mixture in the head-end of secondary combustion chamber, thus the solid volume fraction is smaller. Moreover, the state of Al₂O₃ is mostly solid or solid-liquid mixture, and the solid volume fraction is larger in the low temperature regions.