Flutter analysis of rotating cylindrical shells immersed in a circular helical flowfield of air

Abstract

The aeroelastic stability of a long, thin cylindrical shell with the outer surface exposed to an inviscid, helical flow of ah* is investigated. The cylinder behavior is described by classical shell equations, whereas the aerodynamic forces are described by the linearized potential theory. The approach that is used herein examines the nature of stability of the system when the system is slightly perturbed from its initial equilibrium state. In this paper, numerical results are presented only for the special case of swirl flow around a nonrotating shell, i.e., the axial flow velocity is set to zero. These results indicate that traveling wave type of flutter can be caused by coalescence of backward and forward traveling waves. Two approximate theories are presented and the results are compared.