固冲发动机补燃室非稳态沉积过程分析

摘要

Based on the stochastic trajectory model, the effect on the deposition distribution due to the distorted flow boundary during the unsteady deposition process was investigated by the moving mesh technology. As a result, the unsteady deposition law on the internal wall of the secondary combustion chamber was found. At the same time the groove effect near the inlet exit was analysed. The result shows that the distribution diversity between big particles and small particles is considerable. Moreover,due to the directional changing of gas by the deposition agglomeration the high temperature region near the inlet exit became larger,resulting in the groove. And the deposition rate between the inlets is larger in the initial stage after ignition.%采用随机轨道模型,基于动网格技术,分析了固冲发动机补燃室非稳态沉积过程中燃气流动边界形状变化对燃气流动及沉积分布的影响,得到了补燃室内壁面的非稳态沉积规律,对直连试验中出现的进气道出口拐角"烧蚀沟槽"现象进行了理论分析.研究发现,不同粒径的粒子在补燃室内的分布特性差异较大;凸起的沉积块可改变燃气流向,使进气道出口拐角处的高温区变大,易形成沟槽;点火初期,掺混区进气道之间的沉积速率较大.