AbstractA flying disc can fly through the air because of the combination of the lift and drag forces by the oncoming air flow. In order to clarify the mechanism of flight of flying discs, the flow field structure and the fluid force were investigated on non-rotating and rotating conditions. The disc tested was the official disc for competitions. Using a smoke wind tunnel, flow visualization around the disc was performed in order to understand the effect of disc rotation. The magnitude of tip vortices at the both sides of the disc was different in rotating condition. In the fluid force measurement, lift and drag forces were taken by varying wind speeds, rotational speeds, and angle of attack. Drag and lift forces were found to increase and t...