Impact of stagger angle nonuniformity on turbine aerodynamic performance

The assembling error may lead to variation in stagger angles, which would affect the aerodynamic performance of the turbine. To investigate this underlying effect, two parallel numerical experiments on two turbines with the same profile, but uniform and nonuniform vane stagger angle respectively, were conducted in both steady and unsteady methods. The results indicate that certain changes in the detailed flow field of the turbine occur when the stagger angles are nonuniform, further, the blade loading distribution of the vane and rotor become markedly different from that in uniform vane stagger angle situation. Then these consequences caused by nonuniformity mentioned above enhance the unsteadiness of the flow, finally, the aerodynamic performance changes dramatically. It also shows that, compared with steady simulation, the unsteady numerical simulation is necessary in this investigation.