Ever look out the window and wonder why some airplanes have pointy/upward-pointing bits at the end of wings?

What you see are essentially known as “winglets” and they are standard applications on most aircraft today, if not all.

So why are they there and what do they do?

In simple terms, winglets help reduce the drag associated with the creation of lift.

Although several types of wingtip devices function in different manners, their intended effect is to reduce an aircraft’s drag by partial recovery of the tip vortex energy. Wingtip devices can also improve aircraft handling characteristics and enhance safety for the following aircraft.

Winglets allow the wings to be more efficient at creating lift, which means planes require less power from the engines. That results in greater fuel economy, lower CO2 emissions, and lower costs for airlines.

What they essentially do is help mitigate the effects of “induced drag”. When an aircraft is in flight, the air pressure on top of the wing is lower than the air pressure under the wing. Near the wingtips, the high-pressure air under the wing rushes to the lower-pressure areas on top, which results in the creation of vortices. The vortices flow in a three-dimensional manner over the wings. They not only pull air up and over the wing, but they also pull air back. The third component is induced drag.

VARIOUS TYPES INCLUDE :

Canted Winglet

• Canted winglets are short, upward-sloping wedges and can be found on the Airbus A330 and A340 aircraft and the Boeing 747-400.

Blended Winglet

• The Blended Winglet has a large radius and is designed with a smooth chord variation in the transition area where the wing joins the winglet. This allows optimum aerodynamic loading and avoids vortex concentrations that produce drag.

Split Scimitar Winglet

• The Split Scimitar Winglet redefines the aerodynamics of the existing Blended Winglet on the Boeing 737NG family. The combined aerodynamic elements of the retrofit — ventral strakes, scimitar tips, and trailing edge wedges — provide a drag reduction, and corresponding range increase, of 2 percent or more for long-range missions.

Spiroids

• A futuristic model – Spiroid Winglets, which look like a loop of rigid ribbon at each wingtip were originally tested on the Gulfstream II in 1993 and refined for further proof-of-concept testing on Falcon 50 in 2010.

Raked Wingtip

• Raked wingtips, where the tip has a greater wing sweep than the rest of the wing, are featured on some Boeing Commercial Airplanes to improve fuel efficiency, takeoff, and climb performance.

SOURCE(s)

• en.wikipedia.org
• businessinsider.com
• aviationpartners.com
• COVER PIC : https://www.facebook.com/AirplanesTechnology/photos/aircraft-winglet-types-instagram-account-wwwinstagramcomairplanes_technology/2046347345398874/