摘要
低压透平叶片由于雷诺数较低,叶片边界层大部分区域是层流流动,而低压高负荷叶片,由于负荷的增加导致叶片吸力面尾部逆压梯度增大,层流边界层内能量较低,在大逆压梯度的作用下很容易产生边界层分离,分离的边界层发生转捩,并在叶片吸力面尾部再附。采用三维非稳态N-S方程的大涡模拟方法对典型低压透平叶栅T106不考虑上游尾迹影响的边界层分离、湍流再附等流动现象进行研究,该叶栅基于弦长和喉部速度的雷诺数为5×105,获得的叶栅静压分布、吸力面边界层分离与再附位置与试验数据吻合较好,同时对具有相同雷诺数不同入流角及相同入流角不同雷诺数时吸力面边界层分离再附位置的时空变化、分离泡的尺度以及涡旋非定常动态特性进行了深入研究,得到了2个参数对叶栅边界层分离的影响。
Large fraction of the low-pressure turbine cascade boundary layer is laminar flow due to low Reynolds number. High-lift low-pressure turbine blade leads to increase the adverse pressure gradient at rear of the turbine cascade. Boundary layer separation is easy to happen as the layer has low level of momentum and energy under large adverse pressure gradient, and then transition and reattachment occurs in the boundary layer. Large-eddy simulation （LES） was used to study boundary layer separation and reattachment in the low-pressure turbine （LPT） cascade without considering upstream wakes and at Reynolds numbers（based on chord length and throat exit velocity） of 5×10^5. The numerical results agree with experimental measurements in terms of the time averaged static pressure distribution around the blade and the suction side boundary layer separated and reattached points. In addition, Separation and reattachment locations of suction side boundary layer were investigated with different inlet flow angle and different Reynolds numbers. The effect of the previous two parameters on boundary layer separation of cascade is obtained.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2009年第29期77-83,共7页
Proceedings of the CSEE
基金
国家自然科学基金项目(10602044)
教育部新世纪优秀人才支持计划项目(NCET-07-0682)
国家863高技术基金项目(2009AA04Z102)~~
关键词
大涡模拟
低压透平
边界层
分离再附
large-eddy simulation
low-pressure turbine boundary layer
separation and reattachment
