Wingtips and multiple wing tips effects on wing performance: theoretical and experimental analyses

Abstract

Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.

The purpose of this investigation was to find out how the shape of the wing tip influences the induced drag. The wingtip configurations tested were: blended winglets, raked wingtip, wingtip fence, spiroid winglets and a new configuration called ‘trip le blended winglets’. The wing geometry datawas gathered from the UIUC Database and Airbus website. Simulation was performed at 80 ms -1, which is the take-off speed of the Airbus A380 and Reynolds number of the wing was at 67.12 million, based on the mean aerodynamic chord length, as reference length which was 12.25m. The theoretical analysis was based on the computational fluid dynamic Package (Phoenics), where flow boundary conditions were applied and the discredited Navier- Stokes equations were solved numerically. It was found out that all the wingtip and winglet designs were able to reduce the induced drag and improve the aerodynamic performance. It was also shown how each wingtip configuration works differently and is effective at specific ranges of flight. At cruise angle of attack, raked wingtip offered the highest CL/CD improvement (8.24 %), followed by the wingtip fence (7.64 %). This indicated that raked wingtips are suitable for long ranges and wingtip fence is suitable for mid-long range. At take-off angle of attack, the triple blended winglets offered the highest CL/CD improvement (8.89 %). This result indicated that triple blended winglets are suitable for short range. It was shown that Spiroid winglets work better than blended winglets at both cruise (6.75 % for Spiroid winglets and 6.51 % for blended winglet) and takeoff (7.64 % for Spiroid winglet and 6.94 for blended winglets) and should be considered in the future.