Effect of attack angle on the nonstationary aerodynamic characteristics and flutter resistance of a grid of bent vibrating compressor blades

The angle of attack is studied by experiment for its effect on grid resistance to flutter for a plane compressor grid which includes four translationally vibrating blades. It is established that large critical angles of attack corresponding to stalled flow of blades increase sharply the probability of the occurrence of flutter both for individual blades and for the grid as a whole. It is shown that the reason for this phenomenon is a drop in aerodynamic damping of blades with single vibrations and a marked increase in their mutual aerodynamic effect.Translated from Problemy Prochnosti, No. 10, pp. 78–81, October, 1993.