Numerical simulation about the first stage of a power turbine was performed using 3D viscous code

showing that the details in this turbine stage were captured.And

the flow characteristics of endwalls and blade surfaces for these cascades and the structures of 3D flow field were also presented.After analysis of secondary flow phenomenon and loss mechanism

the evolution process of secondary flow vortex structures in cascade passage(horseshoe vortex

passage vortex

corner vortex

trailing vortex

tip leakage vortex

etc) were revealed

and the effects of vortex structures on loss distribution were also studied.