The effect of wing torsion on aileron-tab flutter

Abstract

This paper gives the results of an investigation into the effects of wing torsion in a ternary-type spring tab flutter. The results presented are for a series of calculations on an idealised system having degrees of freedom in wing pitch, rotation of the control surface and rotation of the tab; the pitching degree of freedom is spring restrained and is intended to represent wing torsion. The tab is restrained as a trim tab or pure aerodynamic servo tab, but the results are expected to apply qualitatively to a spring tab. A comparison is made between these results and those of earlier investigations into a similar problem by Wittmeyerand Wittmeyer and Templeton, where the main surface mode considered was one of vertical translation to represent wing bending. From this previous work criteria were suggested for the prevention of this type of flutter, and in an analogous manner criteria are now tentatively proposed for prevention of wing torsion-aileron-tab flutter.