用于控制透平叶栅内部流动的端部孔隙结构

为利用端部孔隙结构控制叶栅二次流损失,对一种端部孔隙结构在不同攻角下对透平静叶栅内部流场的影响进行数值模拟。结果表明:大负攻角下,该孔隙结构有效地控制了透平叶栅头部压力面的分离泡,减少了损失;在其他攻角下,该结构对该文考察的叶栅没有表现出明显的改善作用。结合该孔隙结构和另一种由原始叶型优化后的叶片进行联合造型,对其在不同攻角下的性能进行了考察。经联合造型后的叶栅与原始叶栅相比在各个攻角下的流动损失均有大幅度降低,大负攻角下效果尤为明显。

Endwall slot model for controlling the flow in turbine cascades

An endwall slot was designed to control turbine cascade secondary flows.Numerical simulations of a turbine stator with the endwall slot at various angles of incidence show that the slot effectively restrains the three-dimensional separation bubble near the leading edge of the pressure surface due to a large negative angle of incidence.The secondary flow loss is reduced by the slot at large negative angles of incidence,but the slot is of almost no use at other angles of incidence.The combination of the slot with an optimized blade design significantly reduces the secondary flow losses compared to the original turbine stator,especially at large negative angles of incidence.