Corner Kick

Let's take a look!

This is an experiment regarding the dynamic lift that works on an object when the object is rotated in an air flow. This experiment was used as a hands-on exhibit of the “Mysteries of Airflow” hosted by the Japan Society of Mechanical Engineers.
When rotation is applied to the ball as it is kicked into the air, a force appears perpendicular to the direction of the flight and the flight path curves. When the ball is made to spin sideways (the rotation axis is in the perpendicular direction), the flight path curves horizontally and the player can aim directly for the goal.
When the flow that strikes the ball is in the direction of rotation, the flow rate (relative speed in this case) decreases at the surface of the opposite direction and the pressure increases. Conversely, the flow rate increases at the surface that is in the same direction as the direction of rotation of flow and the pressure decreases. Due to the right and left pressure difference, dynamic lift works in the horizontal direction and the trajectory of the ball bends (be aware that in fluid dynamics, “dynamic lift” is not limited to an upward force and can indicate a force that is perpendicular to the flow).
This action that generates the dynamic lift on an object rotating in a flow in this manner is known as the “Magnus effect.”
In addition to kicking a soccer ball, this principle is also used with sliders, screwballs, and other balls that curve horizontally in baseball.

[Keywords]	Magnus effect, Bernoulli’s principle
[Related items]	Magnus Pipe, Magnus Cup
[Reference]	The Japan Society of Mechanical Engineers, “The Wonders of Flow (Nagare no Fushigi),” Kodansha Blue Backs, pp. 170–173. Ryozo Ishiwata, “Illustrated Fluid Dynamics Trivia (Zukai Zatsugaku Ryutai Rikigaku),” Natsume Publishing, pp. 196–197 and pp. 90–95. The Japan Society of Mechanical Engineers, “The Wonders of Flow Exhibit” http://www.jsme-fed.org/contests/fushigi.html

Last Update：9.30.2016