槽缝射流对高负荷涡轮非轴对称端壁冷却性能的影响研究

Effects of Slot Jet Flow on Non-Axisymmetric Endwall Cooling Performance in a High-Load Turbine

基于端壁静压分布造型方法,本文针对带有槽缝射流的高负荷涡轮,分别研究了全局及局部造型下端壁冷却性能的变化规律,揭示了不同入射角及槽缝结构对非轴对称造型端壁冷却性能的影响机理。研究表明:非轴对称端壁造型可以显著改变静叶端区气冷特性。造型端壁可通过抑制二次流强度,降低叶栅总压损失系数达0.364%;相比常规端壁,造型端壁冷气有效覆盖面积最大增大13.57%,但横向平均气膜有效度降低;造型端壁可以改善大倾角槽缝射流的冷却效果;使用相切圆弧的槽缝入射段结构后,造型端壁较平端壁有效冷却面积增大了11.51%。

Based on endwall static pressure distribution contouring method,the difference of cooling perfor⁃mance about global and local non-axisymmetric endwall contouring was studied in this research for a high load turbine with purge flow.The effects of incidence angles and slot structures on endwall cooling characteristics of non-axisymmetric contouring were also revealed.The results show that the non-axisymmetric endwall contouring can alter the aerodynamic and cooling performance simultaneously.By inhibiting the secondary flow,the non-axi⁃symmetric endwall contouring can reduce the total cascade pressure loss coefficient 0.364%.The effective area covered by the coolant can increase by 13.57%compared to a flat endwall,but the laterally averaged film effec⁃tiveness is decreased.The non-axisymmetric endwall contouring could improve the protection effect of large angle purge flow.Under the work of tangent circle slot structure,coolant coverage area increases by 11.51%compared with flat endwall.