Numerical Investigation of Winglet Shape Effects on the Aerodynamic Performance of a Rectangular Wing

Abstract

This study investigates numerically the aerodynamic effects of ten winglet configurations mounted on a rectangular wing. Three-dimensional steady incompressible simulations are conducted using ANSYS Fluent package. Spalart-Allmaras turbulence model is used. Simulations are conducted at free-stream velocities of 10 m/s and 30 m/s. Angles of attack are examined from -7° to 15°. The simulated configurations are evaluated using the lift coefficient, drag coefficient, and lift-to-drag ratio. Results show that the blended winglet gives the highest and most consistent aerodynamic-efficiency improvement. The split-tip winglet achieves the maximum improvement of lift, but with a rapid increase in the associated drag. All winglet configurations produce higher drag than the baseline wing at positive angles of attack, while the plate winglet generally causes the largest drag penalties. Comparison of the obtained results with the published numerical data shows generally good agreement in the lift and drag coefficients, particularly at low and moderate angles of attack. The results demonstrate that the winglet selection should be based on their improvements in aerodynamic performance over a range of angles of attack and at different Reynolds numbers.

Keywords: Aerodynamic efficiency; Computational fluid dynamics; Winglet shapes, wingtip vortices.