How winglets work?

How do winglets work?

Image from:- commons.wikimedia.org

If you look at the wing of the aircraft, you will see the bent wing tip. So what is the reason for such bent wing tips? 

Those bent wing tips of the aircraft are known as winglets. Winglets in aircraft are used for the very important purpose. Winglets of aircraft reduce the induced drag produced due to the air above & below the aircraft. If you have read our previous post related to how aircraft fly, then you know that how lift is produced. Air flowing above the wing has more velocity that air flowing below the wing. So, according to Bernoulli's principle higher the velocity lesser the pressure. So Aircraft wing has lesser pressure above the wing & higher pressure below the wing. This pressure difference causes lift.

Image from:- en.wikipedia.org

But due to this velocity difference phenomena, air with the higher velocity above the wing pushes air with lesser velocity below the wing causing the production of vortices(Image is shown above). These vortices are like small tornadoes. These vortices produce drag & reduce lift to the aircraft. As these vortices produce disturbance to the flow of air. 

Image from:- en.wikipedia.org

Richard T. Whitcomb(Image is shown above) concluded that Winglets can be used to reduce drag of the aircraft. By reducing drag aircraft can be made more fuel efficient. The idea about the winglets came from birds. Birds bent their wings while flying to reduce drag.

So aircraft wing tips were bent so that vortices produced due to air velocity difference will be small. So less drag will produce. As bent wing will force vortices to form on the side so that vortices won't disturb airflow.

Using winglets made the aircraft more fuel efficient as the drag of the aircraft was reduced.

Thanks for reading!