prompter: What is a winglet?

assistant: The term "winglet" was previously used to describe an additional lifting surface on an aircraft. It's, essentially, the bendy part on the end of the wing.

According to Wikipedia wingtip devices are intended to improve the efficiency of fixed-wing aircraft by reducing drag.
The upward and outward angles, as well as the size and shape are critical for correct performance and are unique in each application.

Anything else you want to know about winglets?

prompter: Yes please.  What does NASA say about winglets?  For example what does the mathematical equation Cd = Cdo + Cdi quantify?  Lastly, explain the drag coefficient further based on information from NASA website sources.  Thank you.

assistant: NASA has provided extensive information on the factors that affect drag on an aircraft, including the drag coefficient, which quantifies the amount of drag generated by an object. The drag equation states that drag (D) is equal to a drag coefficient (Cd) times the density of the air (r) times half of the square of the velocity (V) times the wing area (A). The drag coefficient is composed of two parts: a basic drag coefficient, which includes the effects of skin friction and shape, and an additional drag coefficient related to the lift of the aircraft, known as induced drag. The induced drag coefficient (Cdi) is equal to the square of the lift coefficient (Cl) divided by the quantity: pi (3.14159) times the aspect ratio (AR) times an efficiency factor (e). The aspect ratio is the ratio of the square of the span to the wing area. Long thin wings have low induced drag, while wings with an elliptical planform also have lower induced drag than rectangular wings, as expressed in the efficiency factor in the induced drag equation. The value of the efficiency factor is 1.0 for an elliptical wing and some smaller number for any other planform, with a value of about .7 for a rectangular wing. 

The Wright brothers, who designed and built the first powered aircraft, learned about induced drag the hard way. Following their first glider flights in 1900, they knew that they had to increase the size of their wings to allow flight in reasonable winds. For the 1901 aircraft, they increased the chord of the wing but kept the span nearly the same, producing a wing with an aspect ratio of 3.0 and high induced drag. The brothers had made mathematical predictions of the performance of their aircraft, but the 1901 aircraft did not meet their range predictions because of lower than expected lift and higher than expected drag. During the winter, with the aid of their wind tunnel, they began to understand the role of induced drag on their aircraft's poor performance. They then designed the 1902 aircraft wing to have a longer span and shorter chord than the 1901 aircraft, changing the aspect ratio to 6.0 with nearly the same wing area. By doubling the aspect ratio, the brothers cut the induced drag in half. The 1902 aircraft was able to meet their performance goals, and they were able to attain glides of over 650 feet.

NASA has also provided information on winglets, which are vertical extensions of wingtips that improve an aircraft's fuel efficiency and cruising range. Winglets reduce the aerodynamic drag associated with vortices that develop at the wingtips as the airplane moves through the air. By reducing wingtip drag, fuel consumption goes down and range is extended. Winglets are designed as small airfoils and are used on aircraft of all types and sizes, from single-seat hang gliders and ultralights to global jumbo jets. Some aircraft are designed and manufactured with sleek upturned winglets that blend smoothly into the outer wing sections, while add-on winglets are also custom made for many types of aircraft. The concept of winglets originated with a British aerodynamicist in the late 1800s, but the idea remained on the drawing board until rekindled in the early 1970s by Dr. Richard Whitcomb when the price of aviation fuel started spiraling upward. NASA extensively studied winglets in an effort to reduce the induced drag on airliners, and they are now one of the most successful examples of a NASA aeronautical innovation being utilized around the world on all types of aircraft.


Sources:

* https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/winglets/

* https://www1.grc.nasa.gov/beginners-guide-to-aeronautics/induced-drag-coefficient/

* https://www.nasa.gov/centers/dryden/about/Organizations/Technology/Facts/TF-2004-15-DFRC.html

* https://wright.grc.nasa.gov/airplane/drageq.html

* https://www.grc.nasa.gov/WWW/K-12////airplane/winglets.html

assistant: NASA has conducted extensive research on winglets and their impact on aircraft performance. Winglets are vertical extensions at the tip of an aircraft's wings that can reduce drag and increase fuel efficiency. NASA has found that winglets can provide significant benefits for commercial and general aviation aircraft.

The equation Cd = Cdo + Cdi is a mathematical expression that represents the total drag coefficient (Cd) of an aircraft. The term Cdo represents the parasite drag coefficient, which is the drag generated by the aircraft's shape and surface area. The term Cdi represents the induced drag coefficient, which is the drag generated by the production of lift. Winglets can reduce the induced drag coefficient and therefore reduce the total drag coefficient.

According to NASA, the drag coefficient is a dimensionless quantity that represents the amount of drag generated by an object in a fluid. In aerodynamics, drag is the force that opposes the motion of an object through a fluid, such as air. The drag coefficient is affected by various factors, including the object's shape, size, and speed. In general, the higher the drag coefficient, the more drag an object will experience.

NASA conducts research on drag reduction techniques, including the use of winglets, to improve aircraft performance and reduce fuel consumption. NASA's research has shown that winglets can reduce the drag coefficient by up to 5%, resulting in fuel savings of up to 5%. Winglets are now commonly used on commercial and general aviation aircraft, and NASA continues to study ways to improve their design and performance.

assistant: A winglet is a small, aerodynamic device that is typically attached at the end of an aircraft's wings. Its purpose is to reduce drag and increase fuel efficiency by improving the lift-to-drag ratio of the wing.

Winglets are designed to minimize the formation of vortices, or swirling air currents, at the wingtips. These vortices occur when high-pressure air flows from the bottom of the wing to the lower pressure area above the wing, creating turbulence and drag. By redirecting the airflow around the wingtip, winglets reduce the size and strength of these vortices, which in turn reduces drag and improves fuel efficiency.

Winglets can come in a variety of shapes and sizes, from simple vertical fins to more complex curved or angled designs. They are commonly found on modern commercial aircraft, as well as some smaller general aviation planes.

prompter: What are they made of?

assistant: Most airplane winglets are made of high-tech polymers.

assistant: Winglets are vertical extensions of wingtips that improve an aircraft's fuel efficiency and cruising range. Wingtip devices are intended to improve the efficiency of fixed-wing aircraft by reducing drag. Although there are several types of wing tip devices which function in different manners, their intended effect is always to reduce an aircraft's drag by partial recovery of the tip vortex energy.

prompter: Does it have any negative effects, such as the extra weight or expenses?