Effects of a Contour Bump on the Unsteady Transonic Aerodynamic Forces of the AMP Wing

Kurzfassung

The effects of a contour bump on steady and unsteady aerodynamics are investigated for both a 2D profile section and a 3D wing, e.g. the AMP model. The supercritical airfoil NLR7301 is chosen as the 2D case for which the shapes of the pressure distributions in steady and unsteady transonic flow demonstrate the differences between the cases with and without bump. For the AMP wing, a 3D bump is shaped in such a maner that it traces the shock area of the elastically deformed wing. Steady and unsteady pressure coefficients are shown for both configurations. The unsteady transonic aerodynamic forces of the AMP wing are subject to flutter calculations. At first comparison of the flutter boundaries with and without bump indicates that the presence of a bump, with its desired effect of drag reduction in transonic flow, also reduces flutter stability for the same physical reasons.