进气道结构对固体冲压发动机补燃室燃烧及内壁流场的影响

为研究进气道结构对固体冲压发动机补燃室燃烧及内壁烧蚀的影响，采用标准k-ε湍流模型，单步涡耗散燃烧模型与KING硼粒子点火燃烧模型，开展了双下侧90°进气结构和双侧180°进气结构固体冲压发动机补燃室内燃气燃烧数值模拟，对比分析了补燃室燃气燃烧流场特征和内壁烧蚀环境特征。结果表明:双侧180°进气结构在补燃室中形成大漩涡，有利于燃气与空气的掺混燃烧，至补燃室出口位置，总燃烧效率超过90%，且该结构有效减少了粒子对内壁的冲刷侵蚀；在双下侧90°进气结构补燃室中，凝聚相粒子和燃气贴近补燃室一侧运动，导致氧气浓度和温度分布不均，不利于燃气的掺混燃烧，总燃烧效率为74%，在远离补燃室进气道一侧形成高温热烧蚀、高浓度粒子侵蚀、高速射流冲刷和热应力集中的综合破坏；双侧180°进气结构的固体冲压发动机补燃室总体性能优于双下侧90°进气结构的冲压发动机补燃室。 

Effect of air-inlet structures on combustion and flow field of inner wall in secondary combustion chamber of solid rocket ramjet

In order to study the effect of air-inlet structures on combustion and ablation combustion chamber of solid ramjet, the flow field characteristics in the secondary in the secondary combustion chamber of solid rocket ramjet with bilateral 180° air-inlet structure and bilateral 90° air-inlet structure on both down sides were analyzed based on the standard k-ε turbulence model, a one-step eddy-dissipation combustion model and combustion mode of boron particles of KING. The results show that large whirlpools are formed in the secondary combustion chamber with bilateral 180° air-inlet structure, which is beneficial to the mixing and combustion of gas and air. The total combustion efficiency of gas phase is 90% at the outlet of the secondary combustion chamber. Moreover, the erosion due to particles is effectively reduced. In the secondary combustion chamber with bilateral 90° air-inlet structure, condensed phase particles and gas move along the unilateral combustion chamber wall, leading to the uneven distribution of oxygen mass fraction and temperature, which are not conducive to combustion of gas. The total combustion efficiency of gas phase is 74%. Comprehensive destruction due to high-temperature thermal ablation, high-concentration particle erosion, high-velocity jet flushing and thermal stress concentration occurs at the side far from the inlet. The overall performance of the secondary combustion chamber with bilateral 180° air-inlet structure is better than that with bilateral 90° air-inlet structure on both down sides.