Negative Magnus force generated on a soft tennis ball

Abstract

There are particularly interesting flights in soft tennis. There are cases where the ball flying while spinning top spins draws a parabola (normal flight) and a trajectory that extends to the back (unique flight). In the experiments conducted by the authors in the past, it was found that the rotational speed can cause negative Magnus force in addition to Magnus force. Various generation mechanisms have been considered for the negative Magnus force, but there are still many ambiguous parts. Therefore, in this study, we aim to clarify the relationship between peculiar flight and negative Magnus force by performing PIV measurement and fluid force measurement, and to supplement the negative Magnus force generation mechanism.