Unsteady Aerodynamic Responses of Mistuned Cascade to Incoming Wakes. Mistuning of Stagger Angle.

Unsteady aerodynamic responses of a mistuned cascade subjected to incoming wakes from the upstream cascade are investigated in this study, here the extended Nishiyama-Funazaki method (1984) is used. Numerical calculations are made, focussing on the effects of restaggering of the cascade. It is accordingly found that there is some possibility of reducing wake-induced unsteady forces by controlling stagger angles without severe expense of cascade performance deterioration. In addition, quasi-steady flow analysis for the unsteady forces is proven to be adequate only in the case of the in-phase incoming condition of the wakes.