Abstract: Turbine profile deviation can hardly be avoided in manufacturing practice, which may affect the behavior of the turbine. To investigate the effect of profile deviation on turbine performance and on details of the flow field, steady and unsteady numerical simulations of a turbine in combination with experiments on a complete engine are carried out and the numerical simulation results are also comprehensively compared. The findings indicate that profile deviation can weaken turbine performance considerably in the whole operating range. It also shows that the unsteady interaction between the blade rows and the structures of the flow field, such as the development of passage vortex and tip leakage flow, the intensity of the leading edge suction spike and the shape and intensity of shock waves, would all alter a great deal as the profile changes. In addition, the results demonstrate that unsteady numerical simulation can capture these influences more precisely.

Key words: profile deviation, turbine, aerodynamic performance, numerical simulation, unsteady