光滑楔形通道径向末端射流冲击冷却换热特性研究

Heat Transfer in Smooth Wedge Channel with Jet Impingement Cooling on Its Radial End

关键词:  叶片冷却  楔形通道  射流  对流换热  冲击冷却

Key words:  Blade cooling  Wedge channel  Jet  Heat convection  Impingement cooling

摘要:

为了研究在旋转状态下射流冲击冷却在楔形通道径向末端的冷却效果，在主流通道进口雷诺数为15000、旋转数为0或0.1的工况下，实验研究了不同射流孔位置、射流流量条件下的楔形通道沿程壁面换热规律。研究结果表明:射流孔附近的通道壁面换热系数被极大地增强，但冷却效果被限制在一定范围内；射流对通道内侧的影响范围要大于中部和外侧，但增大射流流量并不会增加内侧的换热系数；旋转工况下，射流影响区的换热对比静止基本上没有变化；在本实验工况下，射流不能强化沿通道径向射流孔后侧位置的换热；不同工况下的通道整体平均换热在10%以内，末端射流冲击对通道整体换热影响有限。

Abstract:

The present research is focused on internal cooling of wedge channel using jet impingement cooling on its radial end under rotating conditions. Values were presented at Reynolds number of 15000 and Rotation numbers of 0 and 0.1 based on the inlet of main flow passage. The rules of heat transfer on endwall surfaces of wedge channel were studyed for different configurations of jet hole positions and jet flow. One of the present results indicates that the heat transfer coefficients around the jet hole are improved substantially but the effects are limited in the local area. Although the jet cooling has deeper influence on the inner side than other sides，the heat transfer of the inner side has not been intensified by the raise of jet flow. With respect to the heat transfer under rotation conditions，the values of jet impact area are similar to which are under still conditions. Under the experimental conditions，the heat transfer of area on the radial direction over the jet hole has not been enhanced by the jet cooling. At last，integral average heat transfer of channels is within 10% under different conditions，it illustrates that the effects on overall average heat transfer of jet impingement on the channel radial end are limited.