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A frisbee (pronounced ), also called a flying disc or simply a disc, is a gliding toy or sporting item generally made of injection molded plastic and roughly in diameter with a pronounced lip. It is used recreationally and competitively for throwing and catching, as in flying disc games. The shape of the disc is an airfoil in cross-section which allows it to fly by reducing the drag and increasing lift as it moves through the air, compared to a flat plate. Spinning the disc imparts a stabilizing gyroscopic force, allowing it to be both aimed with accuracy and thrown for distance.
A wide range is available of flying disc variants. Those for disc golf are usually smaller but denser compared to ultimate frisbee, and tailored for particular flight profiles to increase or decrease stability and distance. The longest recorded disc throw is by David Wiggins Jr. with a distance of . Disc dog sports use relatively slow-flying discs made of more pliable material to better resist a dog's bite and prevent injury to the dog. Flying rings are also available which typically travel significantly further than any traditional flying disc. Illuminated discs are made of phosphorescent plastic or contain chemiluminescent fluid or battery-powered LEDs for play after dark. Others whistle when they reach a certain velocity in flight.
The term frisbee is often used generically to describe all flying discs, but Frisbee is a registered trademark of the Wham-O toy company. This protection results in organized sports such as Ultimate frisbee or disc golf having to forgo use of the word "Frisbee".
The Morrisons continued their business until World War II, when Walter served in the Army Air Force flying P-47s, and then was a prisoner of war. After the war, Morrison sketched a design for an aerodynamically improved flying disc that he called the Whirlo-Way, after Whirlaway. He and business partner Warren Franscioni began producing the first plastic discs by 1948, after design modifications and experimentation with several prototypes. They renamed them the "Flyin-Saucer" in the wake of reported unidentified flying object sightings.
"We worked fairs, demonstrating it," Morrison told the Virginian-Pilot. The two of them once overheard someone saying that the pair were using wires to make the discs hover, so they developed a sales pitch: "The Flyin' Saucer is free, but the invisible wire is $1.00." () "That's where we learned we could sell these things," he said, because people were enthusiastic about them.
Morrison and Franscioni ended their partnership in early 1950, and Morrison formed his own company in 1954 called American Trends to buy and sell "Flyin Saucers" (no hyphen after 1953), which were being made of a flexible polypropylene plastic by Southern California Plastics, the original molder. He discovered that he could produce his own disc more cheaply, and he designed a new model in 1955 called the Pluto Platter, the archetype of all modern flying discs. He sold the rights to Wham-O on January 23, 1957.
In June 1957, Wham-O co-founders Richard Knerr and Arthur "Spud" Melin gave the disc the brand name "Frisbee" after learning college students were calling the Pluto Platter by that term, which was derived from the Connecticut-based pie manufacturer Frisbie Pie Company, a supplier of pies to Yale University, where students had started a campus craze tossing empty pie tins stamped with the company's logo—the way Morrison and his wife had in 1937.
In November 1957, the Frisbee was featured in what may be the first rock musical ever performed, Anything & Everything, written by Ted Nelson. The game of Frisbee (spelled Frisby) is described in the song "Friz Me the Frisby," as a Frisbee was passed among stooges in the audience. The scene was expressly intended as a way to introduce the game to the audience.
In 1964, Ed Headrick was hired as Wham-O's general manager and vice president of marketing. Headrick redesigned the Pluto Platter by reworking the mold, mainly to remove the names of the planets, but fortuitously increasing the rim thickness and mass in the process, creating a more controllable disc that could be thrown with higher accuracy. Fred Morrison: "Headrick had an eye for product design.... The "New Look" contributed mightily to its phenomenal success."
Wham-O changed their marketing strategy to promote Frisbee use as a new sport, and sales increased. In 1964, the first professional model went on sale. Headrick patented its design; it featured raised ridges (the "Rings of Headrick") that were claimed to stabilize flight.
Headrick became known as the father of Frisbee sports;Victor A. Malafronte (1998). 9780966385526, American Trends Publishing Company. . ISBN 9780966385526 he founded the International Frisbee Association and appointed Dan Roddick as its head. Roddick began establishing North American Series (NAS) tournament standards for various Frisbee sports, such as Freestyle, Guts, Double Disc Court, and overall events. Headrick later helped to develop the sport of disc golf, which was first played with Frisbees and later with more aerodynamic beveled-rim discs, by inventing standardized targets called "pole holes". When Headrick died, he was cremated, and his ashes were molded into memorial discs and given to family and close friends and sold to benefit The Ed Headrick Memorial Museum. Steady Ed Memorial Discs Disc Golf Association
In 1998, the Frisbee was inducted into the National Toy Hall of Fame. In addition, many championships have sprung up around the world and the sport has become very popular, with nine-time champion Miguel Larrañaga from Spain being the leading exponent of frisbee throwing.
Ultimate has a unique standard with a diameter of and a weight of . For competitive uses, WFDF or other official organizations set disc standards to ensure quality.
Each type is designed for a specific purpose, with drivers being used for long-distance throws, mid-range discs for more controlled shots, and putters for short and accurate throws into the target. The rim for golf discs are sharper than ultimate frisbee, to reduce Wind resistance.
Each type of golf disc has hundreds of variations, subject to a uniform requirement in the size of discs: the minimum diameter of a golf disc is .
The object of the game is to advance the disc and score points by eventually passing the disc to a team member in the opposing team's end zone. Players may not run while holding the disc.
The aerodynamic flight of a disc-wing consists of two main changing components, the Lift coefficient (CL), and the Drag coefficient (CD). They are governed by the following.
Where CL0 and CD0 are base lift and drag values of the airfoil itself, based on its geometry, as well as skin friction and Parasitic drag for CD0 6. The other two parameters, CLα and CDα, are the effects that on the lift and drag brought on by changes in the angle of attack (α).
Overall lift and drag for a disc-wing can be calculated from the coefficients of lift and drag using the following equations.
Where ρ is the density of air, A is the surface area of the frisbee and v is the velocity of the frisbee. It is noted that in almost all calculations, the airfoil is approximated as a disc and as such A is calculated through the standard area of a circle formula.
Another contributing factor to the aerodynamics is the pitching moment of the frisbee. This is caused due to an imbalance of the lift force between the front and back ends of the frisbee during the flight, and causes the AOA to change based on the moment it experiences. As such, lift, drag, AOA, velocity in x, y, and z as well as acceleration in x and z change throughout the duration of the flight.
The changes in velocity and acceleration in the z direction are due to a force known as the Robins-Magnis force acting on the frisbee. When a spin is applied, the frisbee experiences a force that causes it to travel in a curved path relative to the ground. As such, depending on the spin that the frisbee experiences, it could drift far to the left or to the right of the thrower, even if a thrown with no z direction velocity, due to the spin that is applied.
Some spin is necessary for stable flight of the frisbee, as the angular momentum self stabilizes in the air and allows for a smooth flight. This is due to the spin causing the frisbee to act as a gyroscope in the air. The roll dynamics and moments that a frisbee experiences play an insignificant role in the flight dynamics of the frisbee.
A common thread across existing research materials is that theoretical results for disc trajectories and performance are checked against data collected in the field. Professional Ultimate and disc golf players are preferred because they provide consistent release speeds and angles of attack.Pozzy T., Getting More Distance - How Important Is Disc Speed, Disc Golf World News, No. 57, Spring 2001. For example, researchers developed a 2D flight dynamics approximation to find the theoretical maximum range an unpowered disk can travel given a set launch speed, and checked it against field tests.Lissaman P.B.S., The Meaning of Lift, AIAA 96-0161, 34th Aero. Sci. Meet & Exhibit, Reno, NV, Jan. 1996.
Sources agree that controlling the trajectory of a frisbee to make landing points repeatable relies on understanding spin rate’s effect on frisbee lift and curve. One study using smoke wire flow visualization and particle image velocimetry measurements determined that spin rate has a slight but noticeable effect on a disk’s aerodynamic drag. At a low AOA (under 5 degrees), the trailing edge vortex strength remained unchanged between spinning and non-spinning tests. However, greater angles of attack allowed rotation to generate a large vortex region that heightened drag.Higuchi H., Goto Y., Hiramoto R. & Meisel I., Rotating Flying Disks and Formation of Trailing Vortices, AIAA 2000-4001, 18th AIAA Applied Aero. Conf., Denver, CO, USA, Aug. 2000. In a similar experiment using a different frisbee design, spin assisted lift across the board but lift enhancement was inversely proportional to the angle of attack.
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