ABSTRACT
An important safety consideration for aircraft in subsonic and transonic flight is an endemic instability known as wing-bending-torsion flutter, which occurs at a high enough speed. Almost all the current work is directed toward numerical computation, merging the FEM NASTRAN codes with the aerodynamic CFD time-marching codes to convert a time-domain waveformapproximating partial differential equations into ordinary differential equations. While this certainly allows “realistic” (nonlinear-complex geometry) wings, it does require numerical specification of parameters, thus limiting generality, and provides little or no insight into the phenomena at work, and, of course, is inadequate for any control design for stabilization (flutter suppression). Indeed, as noted in [10]: “despite computational and experimental research extending over more than 20 years, we do not have a good fundamental understanding of (transonic) flutter.”
