Transonic Buffet Control Research on Supercritical Wing Using Rear-Mounted Bump

Abstract

The transonic buffet over large aircraft wings seriously affects flight safety and ride comfort; hence, improving transonic buffet characteristics by active or passive control methods has been the focus issue of international researchers. Current research shows that shock control bump (SCB) can decrease shock strength effectively at design conditions and improve buffet characteristics by eliminating shock-foot separation. However, SCB will enhance shock strength or produce a secondary shock at off-design conditions. This paper reveals that when the bump was mounted behind the shock position on the upper wing, it can delay the shock-foot separation merged with trailing edge separation in a wide range of free-stream Mach numbers and improve buffet characteristics. Based on the discovery, three-dimensional studies on Wing1, which was released during the Third Drag Prediction Workshop, were presented in this paper. A full-span bump was added on Wing1 at the rearward position behind the shock, and then buffet characteristics of the basic wing and the wing with bump were analyzed using Reynolds-averaged Navier–Stokes and unsteady Reynolds-averaged Navier–Stokes methods. The results show that the bump can improve the buffet performance of Wing1 over a wide range of free-stream conditions; however, it may deteriorate the aerodynamic performance at prebuffet conditions and improve the aerodynamic performance near the buffet-onset conditions.