Investigation of winglet on the transonic flutter characteristics for a wind tunnel test model CHNT-1.

Abstract Winglet is of much practical importance in the aerodynamics of a wing with key features to vibrational modes. To study the influences of both geometry and weight of winglets on flutter characteristics, a semi span version of a supercritical wing for a transport airplane was designed. The flutter model was tested cantilever mounted to a rigid fuselage in the China Aerodynamics Research and Development Center with a series of winglets ballasted. The transonic flutter speed boundary for the wing with a basic winglet was measured at Mach number ranging from 0.6 to 0.89, with a minimum flutter speed near M = 0.85. Influences of both winglet geometry and winglet mass properties were acquired at M = 0.7. The winglet weight was observed to reduce the critical dynamic pressure while the wingtip shape has little influence. The winglet effect with a mass effect rather that an aerodynamic effect on flutter has been verified. Furthermore, a linear function was proposed to quantify the effect of weight on the critical dynamic pressure, and the wingtip mass ballast decreased the q F by 0.125 KPa per gram. [ABSTRACT FROM AUTHOR]