摘要
为了研究旋转涡轮叶片内部冷却通道的换热特性,将叶片内冷通道简化为带90°直肋的旋转双流程方通道,通过旋转加热实验的方式研究了温度比对旋转直肋双通道换热特性的影响。实验进口雷诺数范围为1×104~5×104,旋转数范围为0~2.02,实验平均温度比分别为0.11,0.16,0.20。研究结果表明,与光滑通道实验数据相比,90°直肋削弱了旋转对换热的影响,同时破坏第二通道后缘面附近的不稳定二次流,造成后缘面换热弱于前缘面;温度比是通过改变冷却空气物性与通道内浮升力对旋转通道换内热特性产生影响,温度比的提高引起的物性变化对通道换热具有削弱作用,静止情况下温度比0.20对应的换热与温度比0.11相比,被削弱程度可达16%,而浮升力对换热具有增强作用;低旋转数下,由温度比引起的浮升力作用与物性作用相互中和,高旋转数下温度比的增大对通道换热特性的增强作用更加明显,并且第二通道换热特性受温度比变化影响较第一通道小。
The heat transfer characteristics of rotating cooling channels is investigated. The simplified rotating two-pass channels with 90° ribs were adopted to represent internal cooling channels of the turbine blade when conducting rotating heating experiments to study the effects of the temperature ratios on heat transfer characteristics of the channel. The inlet Reynolds number range from 1×104to 5×104,Rotation number 0 to 2.02,and three different average temperature ratios（0.11,0.16,and 0.20） are selected. As results,90° ribs weaken the influence of rotation on heat transfer comparing with smooth channels,and break the secondary flow near the trailing wall of the second-pass,which cause the weaker heat transfer on the trailing wall than on the leading wall. The temperature ratios affect heat transfer in the channels by changing the physical properties of the cooling air,and heat transfer under temperature ratio TR=0.20 is weakened by 16% compared with TR=0.11,and buoyancy force in channels has positive effects on the heat transfer. Under low rotation number,buoyancy effect counteracts the changes of the physical properties while under high rotation number,the increase of the temperature ratios causes more obvious enhancement effect on heat transfer characteristics. And the first pass is more sensitive to the temperature ratio than the second pass.
出处
《推进技术》
EI
CAS
CSCD
北大核心
2016年第11期2009-2016,共8页
Journal of Propulsion Technology
关键词
涡轮
内冷通道
旋转换热
温度比影响
Turbine
Internal cooling channel
Rotating heat transfer
Wall-temperature ratio effect
