叶尖及尾缘出流条件下内部冷却通道换热实验

为掌握某型高压涡轮叶片叶尖及尾缘出流流量分配比例对内部冷却通道换热特性的影响,利用瞬态液晶测量技术研究不同进口雷诺数、4种出流流量分配比例下局部换热分布规律及平均换热变化趋势.实验结果表明:相同出流流量分配比例、不同进口雷诺数下局部换热分布规律相似,出流流量分配比例对局部换热分布规律有决定性影响,主要体现在第2及第3通道,叶尖出流孔1出流会削弱这两个通道的局部及平均换热;叶尖出流孔2和尾缘间出流流量分配流量比例变化对第1、第2通道的局部及平均换热影响不大,影响主要在第3通道,提高尾缘出流流量分配比例会显著增强第3通道局部及平均换热.

Experiment of heat transfer in internal cooling channel with tip and trailing edge outflows

Detailed local heat transfer distribution and average heat transfer trend at different inlet Reynold numbers with four discharge ratios were acquired by utilizing transient liquid crystal measurement.The purpose of this experimental study is to understand the effect on the heat transfer characteristic of a high pressure turbine blade internal cooling channel with different tip and trailing edge discharge ratios. The results show that: local heat transfer distributions are similar under different inlet Reynold numbers and the same discharge ratio; the discharge ratio has critical impact on local heat transfer distribution, especially in the second and third channels, where local and average heat transfer of these two channels have been weakened by outflow of the first tip hole. Different discharge ratios between the second tip holes and trailing edge have no obvious impact on local and average heat transfer of the first and second channels, but have critical impact on the third channel, while local and average heat transfer of this channel will be enhanced tremendously when the discharge ratio of trailing edge is raised.