Double linearization theory for prediction of mean loading effect on cascade flutter, II: Two-dimensional supersonic cascade

Abstract

In this paper an extension of the improved double linearization theory to two-dimensional supersonic cascades is presented, to predict the mean loading effect on unsteady aerodynamic force on blades in vibrating motion. In the case of supersonic cascades, the aerodynamic instability of the blade motion is significantly affected by the unsteady displacement of shock reflection points, which appears in the linearized formulation as fluctuating concentrated forces acting at mean reflection points. Sample results are presented to demonstrate the effects of blade angle of attack, camber, thickness, Mach number and pitch-chord ratio on the unsteady aerodynamic response. The results show that single-degree-of-freedom bending flutter is more likely to occur for supersonic cascades than for subsonic cascades.