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.