1.5级透平动叶端壁泄漏流换热与冷却研究

Prediction of Heat Transfer and Film Cooling on Blade Platform With Stator-Rotor Purge Flow in a 1-1/2 Turbine Stage

本文数值研究了一级半透平中动静间隙泄漏流对动叶端壁表面换热与冷却的影响,分析了冷气质量流量比、密度比和动叶转速等三个重要因素对动叶端壁表面换热与冷却的作用规律。结果显示,质量流量比和密度比增加会强化端壁上游区域和主通道涡分离线下游区域的换热,但在冷却方面仅在端壁上游区域进一步产生过冷现象而对端壁通道下游的冷却几乎没有任何影响;转速的上升则会削弱端壁换热,并且会抑制通道涡,但对冷气的覆盖面积没有明显的提升作用。

Heat transfer and film cooling on a platform from stator-rotor platform purge flow were numerically investigated in a 1-1/2 turbine stage. The effects of coolant mass flow ratio, coolant-to-mainstream density ratio and rotating speed were examined in detail. The results show that higher mass flow- rates and density ratios could enhance heat transfer level in tile upstream region and the downstream area of the passage vortex lift-off line on the platform, but slightly affected film cooling distributions, particularly in the downstream area. In addition, increasing rotating speed reduced heat transfer over the platform surface. Higher rotating speeds could suppress the passage vortex, but had little effect on film coolant coverage.