正弯涡轮叶栅内旋涡结构的数值模拟

对某型涡轮正弯及直叶栅流场进行了三维粘性求解。给出了马蹄涡及通道涡的详细演化过程。通过对弯直叶栅两类流场拓扑结构上的差异分析，指出与直叶栅相比采用合适的弯角后正弯叶栅有利于形成稳定的通道涡，并且在相当大的轴向弦长范围内保持着这种稳定的涡结构。并将其对损失的影响进行了分析

SIMULATION OF VORTEX STRUCTURE IN BOWED BLADE CHANNEL

Flow fields in a bowed and a straight turbine blade channels were simulated with 3D N-S solver.Generation and development of horse vortex and passage vortex were also considered in detail.There is distinguished difference between topological structure of passage vortex in the bowed blade and that in the straight blade.The passage vortex core is changed from unsteady focus point in the straight blade channel to steady focus point in the bowed blade channel in the most part of the domain.The effect of the topological structure flow pattern difference on energy loss was also analyzed.The steady passage vortex core not only makes passage vortex more tight,but also is beneficial to wrap low energy fluid cumulating in corner into passage vortex to reduce the energy loss of the secondary flow.