Optimal wingtip device design for transport airplane

The present work aims to analyze the feasibility of wingtip device incorporation into transport airplane configurations considering many aspects such as performance, cost and environmental impact. A design framework encompassing optimization for wing-body configurations with and without winglets is described and application examples are presented and discussed.

modeFrontier, an object-oriented optimization design framework, was used to perform optimization tasks of configurations with wingtip devices. A full potential code with viscous effects correction was used to calculate the aerodynamic characteristics of the fuselage–wing–winglet configuration. MATLAB® was also used to perform some computations and was easily integrated into the modeFrontier frameworks. CFD analyses of transport airplanes configurations were also performed with Fluent and CFD++ codes.

Winglet provides considerable aerodynamic benefits regarding similar wings without winglets. Drag coefficient reduction in the order of 15 drag counts was achieved in the cruise condition. Winglet also provides a small boost in the clean-wing maximum lift coefficient. In addition, less fuel burn means fewer emissions and contributes toward preserving the environment.

More efficient transport airplanes, presenting considerable lower fuel burn.

Among other contributions, wingtip devices reduce fuel burn, engine emissions and contribute to a longer engine lifespan, reducing direct operating costs. This way, they are in tune with a greener world.

The paper provides valuable wind-tunnel data of several winglet configurations, an impact of the incorporation of winglets on airplane design diagram and a direct comparison of two optimizations, one performed with winglets in the configuration and the other without winglets. These simulations showed that their Pareto fronts are clearly apart from each other, with the one from the configuration with winglets placed well above the other without winglets. The present simulations indicate that there are always aerodynamic benefits present regardless the skeptical statements of some engineers. that a well-designed wing does not need any winglet.