涡轮平面叶栅设计工况下旋涡结构分析

Vortex Structure of a Turbine Planar Cascade in Design Condition

为了揭示涡轮流道内旋涡结构的空间演化规律,本文采用数值模拟方法对某型涡轮平面叶栅内部流场进行了详细的拓扑分析。首先,利用已有的平面叶栅吹风实验结果对数值模拟结果做了详细的校核,对比结果表明实验结果和数值模拟结果在叶栅气动性能的变化趋势上保持一致,因此用数值模拟结果来定性分析叶栅旋涡结构具有可行性。通过对叶栅流道内部和出口若干个截面上的二次流流线的分析,建立起该涡轮平面叶栅流道旋涡结构,结果表明该叶栅旋涡结构呈上下对称分布,共存在六个旋涡,即上、下马蹄涡、上、下通道涡、上、下集中脱落涡。最终,通过建立叶栅三维定常旋涡结构,明确了叶栅流场内旋涡演化规律。

In order to indicate the evolution rule of the vortex structure in the cascade,it was analyzed in detail by using the numerical simulation method,that the vortex structures ofa certain type of turbine planar cascade.Firstly,this numerical simulation method was existing planar cascade experimental results carefi^lly,and the results show that experimental and numericalsimulation results on the change tendency of tlie cascade aerodynamic performance are consistent,soit is feasible to qualitative analysis of the vortex structure by the results of numerical simulation.Throughbotli internal and export sections of cascade p asage,the secondary flow streamlines were analyzed,andthen vortex structure of the turbine planar cascade were established,the results show that the distributionof t!ie vortex structure is symmetrical,altogether there are six vortexes,namely the up and down horseshoevortex,the up and down passage vortex,the up and down concentrated shedding vortex.Finally,through the establishment of three-dimensional unsteady vortex structures of this turbine cascade,it hasbeen clear about tiie evolution rule of tiie turbine cascade flow field.