微型涡喷发动机燃烧室全覆盖气膜冷却

为了延长微型涡喷发动机燃烧室的使用寿命，针对燃烧室壁面高温区进行全覆盖气膜冷却研究. 在KJ-66微型涡喷发动机试车实验的基础上，比较实际燃烧工况下，排布方式和燃烧室外环的扩张孔对气膜冷却效果及燃烧室整体性能的影响. 结果表明，在实际微型涡喷发动机模型中，顺排的平均综合冷却效率低于叉排，但对壁面的综合降温效果优于叉排. 随着扩张孔出口直径的增大，气膜冷却效果逐渐改善，但会影响燃烧室出口温度分布的均匀性. 由于燃烧室后排冷却孔的影响，二次流射入主流会发生偏转，提升了气膜的冷却效果. 整体而言，全覆盖气膜冷却在实际燃烧工况下对燃烧室壁面有着很好的冷却作用，扩张型气膜孔能够有效改善燃烧室外环的气膜冷却效果.

Full-coverage film cooling in combustor of micro gas turbine

The full-coverage film cooling was analyzed for the high temperature area on combustor in order to prolong the service life of the micro gas turbine combustor. The effects of arrangements and outer ring expansion film holes on the film cooling and the overall performance of combustor were compared under the actual conditions based on the test of KJ-66 micro gas turbine. Results showed that the average overall cooling efficiency of the order arrangement was lower than that of the cross arrangement in the actual micro gas turbine model, but the comprehensive cooling effect was higher. The film cooling effect was gradually improved as the outlet diameter of expansion holes increased, but the uniformity of temperature distribution at the combustor outlet was decreased. The secondary flow into the mainstream was deflected due to the influence of the cooling holes at the back of the combustor, which can improve the effects of film cooling. The full-coverage film cooling has a good cooling effect on the combustor wall under actual combustion conditions. Expansion film holes can effectively improve the film cooling effects of the combustor outer ring.