摘要
针对多层涡轮机匣内部典型阵列冲击/气膜,试验研究了横流出流和气膜出流作用对冲击冷却靶面换热系数的综合作用。重点分析了非均匀阵列冲击射流中,冲击雷诺数(6 750~28 500)、横流出流比(0~0.5)等参数对冲击靶板局部和平均努赛尔数的影响。试验中局部和平均努赛尔数均随着冲击雷诺数的增加而提高。当横流出流比增加后,局部和平均努赛尔数均减小。试验结果表明,气膜孔和冲击孔间距较小的工况下能够获得更好的局部换热强化效果。横流出流的存在,削弱冲击射流带来的局部强化冷却作用,并且随着出流比的增大,这种换热削弱程度也逐步变大。
Experimental studies are performed to investigate the cooling performance for the typical jet array impingement/film cooling configurations within the multi-layer turbine casing. Regarding to the non-uniform impingements, the effects of jet crossflow and film cooling on heat transfer coefficients on the target plate are studied, i.e. the jet Reynolds numbers （6 750--28 500） and the outflow to crossflow ratios （0--0.5）. It is found that the local and area-averaged Nusselt numbers are enhanced as the impingement Reynolds number increases. While they decrease gradually with a larger outflow to crossflow ratio. The results indicate that higher local Nusselt number will be obtained with a smaller distance be- tween the film hole and the jet hole. The enhanced heat transfer induced by impingement is weakened due to the extraction of crossflow. This phenomenon becomes to be more distinguished when the out- flow to crossflow ratio increases.
出处
《南京航空航天大学学报》
EI
CAS
CSCD
北大核心
2017年第3期376-381,共6页
Journal of Nanjing University of Aeronautics & Astronautics
基金
南京航空航天大学研究生创新基地(实验室)开放基金(kfjj20160202)资助项目
中央高校基本科研业务费专项基金资助项目
关键词
涡轮机匣
冲击/气膜复合冷却
横流
横流出流比
换热系数
turbinecase
impingement/film compound cooling
cross flow
extraction flow of crossflow
heat transfer coefficient
