This study numerically investigates the axial slot film cooling of a stochiometric hydron/air rotating detonation engine. The essential flow characteristics are analyzed, and application prospects are explored. An annular liner is positioned at the inlet of the engine, partitioning the combustion chamber into a cooling passage and a combustion channel. Air is injected through the cooling channel to establish a protective low-temperature film along the outer wall. The thermal performance of three different liner lengths is evaluated, with all configurations achieving an average cooling effectiveness above 0.4 near the engine outlet. However, challenges arise from increased temperature due to deflagrations in the boundary layer and the disruption of cooling film by detonation products. Comparative evaluation of the three liner lengths indicates that a more extended liner enhances cooling effectiveness by mitigating the blocking effect. With the shortest and medium liners, the average cooling effectiveness decreases to 0.93 and 0.98, respectively, at 0.01 m upstream from the exit of the cooling channel. In contrast, the most extended liner maintains cooling effectiveness near unity. Despite a slight increase in instability of the longest liner, all configurations achieve a specific impulse exceeding 5800 s and a pressure gain over 0.25. The differences in propulsive performance among the liners are negligible, with the medium-length liner displaying a 0.30 % and 0.69 % higher average thrust compared to the shortest and longest liners, respectively. Based on these results, a liner exceeding the height of the detonation wave is finally recommended, offering a balance between propulsive performance and cooling effectiveness.

中文翻译：

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旋转爆震发动机轴向气膜冷却不同衬套长度的数值研究


本研究对化学计量水氢/空气旋转爆震发动机的轴向槽膜冷却进行了数值研究。分析了其基本流动特性，并探讨了应用前景。环形衬套位于发动机的入口处，将燃烧室分隔成冷却通道和燃烧通道。通过冷却通道注入空气，沿外壁建立保护性低温膜。对三种不同长度的衬套的热性能进行了评估，所有配置在发动机出口附近均实现了 0.4 以上的平均冷却效率。然而，边界层爆燃和爆炸产物破坏冷却膜导致温度升高，带来了挑战。对三种衬套长度的比较评估表明，更长的衬套可以通过减轻阻塞效应来增强冷却效果。对于最短和中等衬里，在冷却通道出口上游 0.01 m 处，平均冷却效率分别降至 0.93 和 0.98。相比之下，最延伸的内衬保持接近一致的冷却效率。尽管最长衬管的不稳定性略有增加，但所有配置均实现了超过 5800 s 的比冲和超过 0.25 的压力增益。衬管之间推进性能的差异可以忽略不计，与最短衬管和最长衬管相比，中等长度衬管的平均推力分别高出 0.30% 和 0.69%。根据这些结果，最终推荐使用超过爆轰波高度的衬套，以实现推进性能和冷却效率之间的平衡。