大子午扩张涡轮导向器栅内流动控制研究

Investigation of Flow Control in Vane Guide Channel of a Large Meridional Expansion Turbine

大子午扩张跨音涡轮具有外端壁栅道前附面层偏厚和内端壁栅道内激波附面层干扰分离严重的特点,从而导致导向器栅道内流动损失偏高。采用全三维黏性N-S方程对优化设计获得的先进导向器叶型和原型进行了级环境的数值仿真,并对比分析了通过多截面S1型线联合设计改善栅道内全三维流动的控制机理。结果表明:采用根部缩放型线和中上部收缩型线能够改善大子午扩张跨音涡轮导向器栅道内流动,此种S1流面设计能减薄外壁侧来流附面层,并减弱甚至消除根部出口激波附面层干扰以及分离的径向掺混。

Large meridional expansion transonic turbine has the characteristics of the thick boundary layer on shroud and the boundary layer separation with shock wave interference on hub,so the flowing loss is higher that in vane guide channel.The optimize design better vane guide and the original one were simulated through the full three-dimensional viscosity navier-stokes equation,and the flow control mechanism was comparative analyzed that the more section S1 combined design can improve the three dimensional flow. The results showed： using the shrink-release S1 profile in roof and the shrink S1 profile in other span,the boundary layer is thinner on shroud,and the boundary layer separation is weakened on hub,even eliminated,therefore the flow loss is reduced that in vane guide channel.