Transonic Flutter Analysis of a Rectangular Wing with Conventional Airfoil Sections

Abstract

Flutter analysts have encountered considerable analytical difficulties in the prediction of the flutter stability of aircraft operating in the transonic Mach number regime. Because of the shocks and nonlinearities of transonic flow the aerodynamic unsteady forces have been difficult to determine and have prohibited accurate determination of the flutter speed. The finite-difference relaxation method is used to determine the oscillatory transonic aerodynamic forces on a uniformly stiff cantilever rectangular wing in a flow field with mixed subsonic and supersonic regions together with shock waves. The flutter speed is determined at two transonic Mach numbers and is compared to the flutter speed obtained using a linear aerodynamic theory.