尾缘流量分配对涡轮叶片内冷通道换热影响的实验研究
Experimental Investigation of the Influence of Trailing Edge Outflow Rate Allocation on the Heat Transfer in Turbine Blade Internal Cooling Channe

为掌握某型高压涡轮叶片尾缘出流流量分配比例对叶片内部通道换热特性的影响,根据相似原理采用几何放大模型,利用瞬态液晶测量技术研究了进口雷诺数为27 000、24 000时,5种尾缘出流比下的通道换热特性,获得了通道局部换热分布规律及平均换热变化趋势。实验结果表明:尾缘出流比变化对尾缘通道局部换热分布规律影响最为显著,对中间通道影响明显,对前缘通道影响不明显;中间通道及尾缘通道展向平均换热均随尾缘出流比增大而先增强后减弱,出流比为25％时,通道展向平均换热最强,而前缘通道受影响不明显;各通道及测量面平均换热随尾缘出流比增大均先增强后减弱,在出流比为25％时,平均换热最强;尾缘出流比在0～1范围变化对尾缘通道平均换热影响幅度最大,约为30％,中间通道次之,约为20％,前缘通道最小,约为10％。
Detailed local heat transfer distribution and average heat transfer variation trend of five different trailing edge outflow rate allocation ratios, with the inlet Reynolds number of 27 000 and 24 000 and in proportionally enlarged model according to similarity principle, were acquired by using transient liquid crystal measurement technique. The purpose of this experimental study is to understand the effect on the heat transfer characteristics of high？？pressure turbine blade internal cooling channel with different trailing edge outflow rate allocation ratios. The results show that different trailing edge outflow rate allocation ratios will affect the local heat transfer distribution in trailing edge tunnel remarkably and in middle tunnel obviously, but in leading edge tunnel invisibly; the spanwise average heat transfer in the middle and trailing edge tunnels is enhanced firstly and then depressed with the increase of trailing edge outflow rate allocation ratio, and enhanced mostly at the ratio of 25％, but invisibly in leading edge tunnel; the average heat transfer of each tunnel and measurement surface is strengthened firstly and then depressed while increasing the trailing edge outflow rate allocation ratio, and is also strengthened mostly at the ratio of 25％; different trailing edge outflow rate allocation ratios affect the average heat transfer in each tunnel, mostly in trailing edge tunnel, about 30％; posteriorly in middle tunnel, about 20％; and leastly in leading edge tunnel, only 10％