Physics and Control of Transonic Buffet

Abstract

The flight envelope of an aircraft operating at high subsonic velocities is bounded by several limitations, one of these consists in thewing experiencing oscillations of a shockwave on its suction side for a certain range ofMach number (Ma), angle of attack (®) and Reynolds number (Re). This phenomenon is referred to as transonic buffet and it may ultimately result in violent structural oscillations of the wing (the so-called buffeting), in addition to the oscillations of the aerodynamics loads. Notwithstanding the relevance of this topic, there is not yet an only explanation regarding its mechanism, therefore, the first aim of this experimental project is to obtain further insight on the physics of transonic buffet (Part I). As a second objective, in Part II different strategies for the control of buffet have been investigated. The experiments of this study have been carried out in the transonic-supersonic wind tunnel of TUDelft on supercritical airfoil and wings based on theOAT15A airfoil. The behavior of this phenomenon has been scrutinized using optical experimental techniques, such as particle image velocimetry (PIV), schlieren, and, background oriented schlieren (BOS)...