Parametric Design Study of Rigid Single Element Devices at High Speed and Aerodynamic Assessment at Low Speed Including Investigations on Moving Parts

Abstract

A parametric analysis of several types of rigid winglet geometries was cariied out at cruise condition using a rapid databased aerodynamic prediction method. The optimised configurations were obtained according to an effective drag approach, which takes into account aerodynamic improvements and structural penalties. The most promising device found was a highly swept, off-loaded anhedral wing tip device with a reduced chord length. For low speed assessment study, both clean and take-off configurations were used. The designed winglet has shown poor flow behaviour at low spped regime due to the design objetive at cruise. To improve the performance at low speed, moving parts and redesigned winglet airfoils were performed. The design study of both geometry modifications is described. The results obtained were confirmed by RANS computations. The resulting geometry provides great benefit at high and low speeds relative to the reference geometry. additionally, a brief design work of a conventional wing tip device was conducted to gain a better understanding of the benefit of the anhedral winglet. Finally, a wing tip shape study was carried out using a Shark winglet.