Numerical Investigation of a Spoiler Effect on the Transonic Flutter Boundary

Abstract

In this paper, the effect of a statically deflected spoiler on the transonic flutter boundary is investigated by means of numerical models. For this purpose, a spoiler geometry is added to the NACA64A010 airfoil and a wing cross-section of the NASA's Common Research Model. As basis for flutter analyses, unsteady aerodynamic loads are obtained with a linearized CFD-method in the frequency domain. The flutter results show an increase in the flutter stability boundary in the transonic dip region due to the spoiler deflection. However, this effect is very sensitive to the spoiler parameters. Especially at high Mach numbers, deterioration in the flutter stability boundary can be found for some specific spoiler deflection angles. A careful use of the spoiler and a dedicated scheduling scheme dependent on the Mach number are therefore suggested, if the spoiler effect is exploited as part of future flutter suppression technologies.