叶片冷却的静叶时序对涡轮的性能影响

燃气轮机工作过程中上游叶片的尾迹会周期性地扫掠下游叶片,这使得下游叶栅通道内的流场呈现显著的非定常性。而时序效应作为一种典型的非定常流动现象,已受到国内外学者的广泛关注。本文研究双级气冷涡轮,利用全三维非定常数值仿真的方法分析了第1级与第2级静叶之间的时序位置对涡轮流量和效率的影响。计算结果表明处于不同时序位置下的涡轮第2级静叶叶身冷气流量的差异可达15.6%,涡轮41截面效率和热效率的波动幅值则分别达到了0.33%和0.26%。涡轮冷气流量的变化一定程度上影响了41截面效率,但时序位置对下游叶栅通道流动损失的影响才是造成涡轮效率差异的主要原因。

Stator Clocking Effect on Aerodynamic Characteristics in Cooled Gas Turbine

The interaction between rotor and stator airfoils in gas turbine causes an inherently unsteady flow field. Clocking effect, as one of the typical unsteady flow effects, has aroused extensive attention in scholars. Presented study is conducted in a two-stage cooled turbine, with unsteady Reynolds-average Navier stokes(URANS) method employed to investigate the influences of stator airfoil clocking effects on mass flow and efficiency characteristics. Computational results show that the difference of second stage cooling air could be approximately 15.6%, and the amplitude of turbine 41-section efficiency and thermodynamic efficiency fluctuation are 0.33% and 0.26% respectively. Variation of second stage cooling air would impact 41-section efficiency to a certain extent, however, extra profile losses caused by clocking effect play a more important role on turbine efficiency fluctuation.