Flying Disc - Physics

Physics

Lift is generated in primarily the same way as a traditional asymmetric airfoil, that is, by accelerating upper airflow so that a pressure difference gives rise to a lifting force. Small ridges near the leading edge act as turbulators, reducing flow separation by forcing the airflow to become turbulent after it passes over the ridges.

The rotating flying disc has a vertical angular momentum vector, stabilizing its attitude, not altitude, gyroscopically. Depending on the cross-sectional shape of the airfoil the amount of lift generated by the front and back parts of the disc can be unequal. If the disc were not spinning, its absence would tend to make it pitch. When the disc is spinning, however, such torque would cause it to precess about the roll axis, causing its trajectory to curve to the left or the right. Most discs are designed to be aerodynamically stable so that this roll is self-correcting for a fairly broad range of velocities and rates of spin. Many disc golf discs, however, are intentionally designed to be unstable. Higher rates of spin lead to better stability, and, for a given rate of spin, there is generally a range of velocities that are stable.

Even a slight deformation in a disc (called a "taco," which in extreme cases looks like a taco shell) can cause adverse effects when throwing long range. It can be observed by holding the disc horizontally at eye level and looking at the rim while slowly rotating the disc.