扇形叶栅通道中密度比和流量比对叶片表面全气膜冷却特性的影响

Effects of Density Ratio and Mass Flow Rate Ratio on Vane Full Coverage Film Cooling Characteristics in Fan-Shaped Cascade Tunnel

关键词:  气膜冷却效率  密度比  流量比  扇形通道  三维叶片

Key words:  Film cooling effectiveness  Density ratio  Mass flow rate ratio  Fan-shaped tunnel  Three-dimensional vane

摘要:

为了研究扇形通道中真实弯扭导向叶片全气膜冷却特性，采用压敏漆（PSP）测试技术实验测量了叶片全气膜冷却效率，获得了不同密度比（1.0， 1.5）和质量流量比（9.71%， 11.64%，12.47%）对叶片全气膜冷却效率的影响规律。结果表明：密度比1.0条件下，随着流量比增加，叶片压力面侧气膜冷却效率逐渐增加，叶片吸力面侧靠近前缘区域气膜孔下游的冷却效率减小；密度比增加可以使叶片整体气膜冷却效率提高，其中压力面前侧靠近前缘区域的冷却效率提高最为明显，最多提高了182%；密度比1.5条件下，增加流量比仅会使得压力面侧中弦区域的气膜冷却效率小幅度增加。

Abstract:

To study the full coverage film cooling characteristics of the actual twisted vanes in the fan-shaped cascade tunnel， the pressure sensitive paint （PSP） measurement technique is used to measure the full coverage film cooling effectiveness of turbine guide vane. The effects of the density ratio （1，1.5） and mass flow rate ratio （9.71%，11.64%，12.47%） on the film cooling effectiveness have been researched in the current paper. The results are as follow： Under the 1.0 density-ratio condition， the film cooling effectiveness of the vane pressure surface increases monotonically with increasing mass flow rate ratio. However， with the increase of the mass flow rate ratio， the film cooling effectiveness near the leading edge gradually decreases in vane suction side downstream the film hole. With the density ratio increasing， the film cooling effectiveness of the whole vane surface increases， particularly near the leading edge at pressure side， and the maximum increase is 182%. Under the 1.5 density-ratio condition， increasing mass flow rate ratio has a slight effect on the span-wise averaged film cooling effectiveness in the mid-span region of the pressure surface.