What is the function of winglets?

What is the function of winglets?

• A. Increase lift at all speeds
• B. Improve structural rigidity of the wing
• C. Increase fuel efficiency at high speeds only
• D. Reduce induced drag by weakening wingtip vortices

Answer: (D)

Winglets reduce induced drag by weakening wingtip vortices. When a wingmakes lift, air spills from the high-pressure underside to the upper surface, curling around the wingtips and forming vortices that trail behind the wing. These wingtip vortices create a downwash and an associated drag component called induced drag, which is especially noticeable when lift is high or at lower speeds. Winglets act as small vertical surfaces at the wingtips that redirect some of that flow outward and upward, weakening the vortices and lessening the downwash. With weaker vortices, induced drag drops, improving engine efficiency and overall range, particularly during cruise where this drag component matters most. They don’t magically increase lift across speeds, they aren’t primarily about structural rigidity, and their benefit isn’t limited to very high speeds—their main aerodynamic impact is reducing induced drag by curtailing wingtip vortices.

Winglets reduce induced drag by weakening wingtip vortices. When a wingmakes lift, air spills from the high-pressure underside to the upper surface, curling around the wingtips and forming vortices that trail behind the wing. These wingtip vortices create a downwash and an associated drag component called induced drag, which is especially noticeable when lift is high or at lower speeds. Winglets act as small vertical surfaces at the wingtips that redirect some of that flow outward and upward, weakening the vortices and lessening the downwash. With weaker vortices, induced drag drops, improving engine efficiency and overall range, particularly during cruise where this drag component matters most. They don’t magically increase lift across speeds, they aren’t primarily about structural rigidity, and their benefit isn’t limited to very high speeds—their main aerodynamic impact is reducing induced drag by curtailing wingtip vortices.