温度比对导叶端壁冷却特性的影响

Effect of temperature ratio on cooling characteristics of vane end-wall

利用高温风洞及远红外热像技术,在两种主流/冷气温度比(1.53和2.29)和3种冷气/主流质量流量比(0.50%,1.25%和1.50%)下,研究了温度比对导叶端壁综合冷却特性的影响。对比高、低温比下的实验结果发现:保持冷流温度不变,通过增加主流温度来提高温比,会使整个端壁表面冷却效率却显著增加;高温比改变了端壁表面的冷却特性,端壁不同位置冷却效率在高温比时增加的幅度不同,端壁高、低冷却效率区发生变化,适用于低温比的气膜孔布局方案可能并不适用于高温比;温比对端壁前缘冷却特性的影响较大,对端壁尾缘的影响较小。

Experimental investigations of the cooling characteristics of a vane end-wall were carried out in a hot wind tunnel using infrared thermograph technique.Two mainstream-to-coolant temperature ratios of 1.53 and 2.29,and three coolant-to-mainstream mass flow ratios of 0.50%,1.25%and 1.50%were chosen.Comparing the results obtained at high and low temperature ratio,the following three conclusions can be drawn.The experimental method of increasing the temperature ratio by increasing the mainstream temperature and keeping the coolant temperature constant led to a significant increase in the overall cooling effectiveness of the end-wall surface.The cooling characteristics of the end-wall surface changed as the temperature ratio increased.As the temperature ratio had different effect of cooling effectiveness at different positions of the end-wall,the areas with high and low cooling effectiveness changed.The scheme of hole-layout suitable for low temperature ratio may not be applicable to high temperature ratio.The effect of temperature ratio on the cooling characteristics was great at the leading edge,but not evident at the trailing edge.