小展弦比透平动叶栅二次流涡系演变及气动特性数值分析

采用控制容积积分法和协调一致压力修正算法数值求解三维稳态时均N-S方程组,对一小展弦比透平动叶栅在旋转状态下的二次流涡系演变和三维气动特性进行了分析。计算结果表明,该叶栅上下端壁通道涡在叶展中部交汇,在该处产生强烈的横向流动并引起叶展中部能量损失急剧增加,使损失沿叶高的分布由常见的双驼峰型变为单驼峰型,同时还使叶展中部出口气流的欠偏转角大幅度增大。

NUMERICAL ANALYSIS OF THE DEVELOPMENT OF SECONDARY FLOW VORTICES AND AERODYNAMIC CHARACTERISTICS OF A SMALL ASPECT RATIO TURBINE ROTOR CASCADE

The development of secondary vortices and the aerodynamic characteristics of a small aspect ratio turbine rotor cascade in moving state are analyzed by solving the three-dimensional time-averaged Navier-Stokes equations using control volume method and consistent pressure-correction technique. The results show that the passage vortices near the upper and lower endwall encounter and mix with each other at the midspan which causes a strong traverse flow and the local energy loss increment; meanwhile, results in longitudinally a single-peak profile of the pitch-aver aged loss distribution different from the usual dual-peak profile. Moreover, the under-deflection of the exit flow at the midspan of cascade increases significantly.