透平动叶栅二次流涡系演变及气动特性的数值模拟  

Numerical Simulation of the Development of the Secondary Flow Vortices and Aerodynamic Characteristics of a Turbine Rotor Cascade

作　　者：朱光宇[1] 俞茂铮[1] 程代京[1] 

机构地区：[1]西安交通大学能源与动力工程学院,西安710049

出　　处：《西安交通大学学报》2002年第11期1142-1146,共5页Journal of Xi'an Jiaotong University

摘　　要：采用控制容积积分法和协调一致的求解压力耦合方程的半隐算法 ,数值求解了三维稳态时均N S方程组 ,并应用可实现k -ε湍流模型 ,计算分析了低展弦比透平动叶栅二次流涡系的演变特点及叶栅气动特性 .计算结果与现有的试验结果吻合良好 ,表明所用的数值方法及湍流模型适用于模拟存在复杂涡系的叶栅流动 .计算结果表明 ,与静叶栅相比较 ,由于动叶栅的折转角较大 ,且气流膨胀加速程度较小 ,通道内横向压力梯度对涡系的发展及叶栅的气动特性产生了更为显著的影响 ,使得马蹄涡压力面分支在叶栅流道进口区域即与端壁上的横向流动相融合 ,并很快发展成强度较大的通道涡 ,马蹄涡吸力面分支也会较早地受到通道涡的卷吸而消失 ,以致叶栅的能量损失显著增大 ,出口气流角沿高度方向分布也很不均匀 .The development of the secondary flow vortices and aerodynamic characteristics of a low aspect ratio rotor cascade is numerically analyzed by using the control volume approach and SIMPLE-Consistent algorithm to solve the three-dimensional steady time-averaged N-S equations closed with the realizable k-ε turbulence model. The computational results are in good agreement with the available experimental results and show that the applied numerical method and turbulence model are suitable for simulating the cascade flow with complex vortex-system. The results also show that in comparison with the stator cascade, the cross pressure gradient in the rotor cascade passage has stronger influence on the vortex development and areodynamic characteristics because of the larger turning angle and less acceleration of flow. Therefore, the pressure side leg of horse shoe vortex is already merged with the cross flow on end wall at the inlet domain of passage and then a strong passage vortex forms shortly. The suction side leg of horse shoe vortex is also earlier rolled up and then sucked in by passage vortex. As a result,the energy loss is significantly larger than that of the stator cascade and the spanwise distribution of outlet flow angle is non-uniform.

关 键 词：透平 气动特性 动叶栅 二次流 涡系演变 数值模拟 控制容积积分法 k-ε湍流模型 

分 类 号：TK262[动力工程及工程热物理—动力机械及工程]