The effects of unsteady interactions on blade flutter

摘要

THE stall flutter of steam turbine long blade influences the operation safety of the large steam turbine. Some basic assumptions have been used in steam turbine flutter study, including the assumption that the interblade phase angle distribution alongthe blade row is constant. This assumption simplifies the computation of unsteady flow around oscillating cascade, because the flow through a cascade channel can represent the whole channels in the rotor. But the experiments about the stall flutter of steam turbine show that the interblade phase angle distribution along the blade row is not constant. Especially the interblade phase angle distribution of grouped blades cannot be taken as constant.