端壁边界层抽吸对透平静叶栅二次流影响的数值研究

Effect of Endwall Boundary Layer Suction on Secondary Flow of Turbine Stator Cascade

湿蒸气透平静叶栅的端壁抽吸槽常用来抽除沉积水膜以防止动叶片水蚀，但它也有可能同时用来抽除端壁上边界层以抑制二次流的发展．作者采用有限体积差分法求解了三维稳态时均ＮＳ方程组，分析了在叶栅前缘附近进行端壁边界层抽吸对透平静叶栅二次流流场、气流偏转角及总压损失系数等气动特性参数的影响．计算结果表明，在前缘附近抽吸端壁边界层可以抑制马蹄涡的发展，减弱通道涡的强度，从而减小二次流损失并提高出口气流的均匀性．

The suction slot on the endwall of wet steam turbine stator cascade is used to remove the water deposited film so as to prevent the rotor blade from erosion. It can also be used to suck out endwall boundary layer for restraining the development of secondary flow. The effects of endwall suction near the leading edge of the cascade are studied. Finite volume difference method for solving the steady three dimensional time averaged Navier Stokes equations is applied to analyze the effect of suction on the secondary flow field,the yaw angle and the total pressure loss coefficient of a turbine stator cascade. The results show that development of horseshoe vortex could be restrained and the passage vortex could be weakened. The loss caused by secondary flow is thus reduced and the uniformity of the outlet flow field is improved.