Winglets and Planes
A winglet is a special wingtip device made to improve a fixed wing aircraft's efficiency. The goal of a wingtip is to enhance aerodynamic effects on the plane's wake, which also makes handle characteristics better. In addition, winglets can improve the overall look of the plane, giving it a more up-to-date appearance. The bottom line is that a winglet increases the wing's ratio while not adding wingspan.
When in flight, winglets reduce induced drag so parasitic drag is increased. Therefore, the strength and weight of the wing is increased. Additionally, winglets help by increasing lift generated at the wingtip while at the same time, reducing lift-induced drag. Again, in addition to improving overall performance, winglets also equate to better fuel efficiency!
You will find a number of different winglet types, each with the same result but made somewhat differently. As a near vertical extension of the wingtip, the upward angle, coupled with inward angle, size, and shape make a huge difference in the plane's performance. Although a small addition to the plane, the difference made can benefit the plane throughout its lifetime.
Of course, for winglets to provide solid benefits, proper installation and maintenance are crucial. Keep in mind that there is a cost involved with both installation and maintenance. However, compared with the benefits, the cost is often well worth it. For instance, as planes travel through vortices, they experience turbulent air. With this, some degree of control over the aircraft is lost, which in some cases could be devastating. However, winglets produce less vortice, meaning planes in the same flight path are not affected nearly as much, making this a huge safely benefit.
Now, not all aircraft use basic winglets. For instance, a large Boeing 747-8 or 777 would have trouble maneuvering gates due to size. Therefore, they will go with raked winglets. This means the larger size winglets are typically used only for short distance flights, helping with climb performance. Interestingly, winglets were first used by NASA in 1979. First developed in 1897, the concept of winglets has changed dramatically over the years to becoming a great design option for many planes.
Another option is called blended winglets, which is used on the Boeing 737. In this case, the interference drag is reduced at the wing and winglet junction. What happens is that a significant interior angle interacts with the boundary layer flow. In return, a drag-induced vortex is created, which benefits the winglet. Now, while there are performance benefits with the blended winglets and a number of manufacturers are retrofitting planes, they are more for aesthetics.