235 The Measurement of the Negative Magnus Force on a Table Tennis Ball

Abstract

The negative Magnus force was observed on a sphere at the moderate Reynolds number and the moderate spin rate which is defined by the ratio of the circumferential velocity to the free stream velocity. This region matches the forehand smash in a table tennis game according to the result of Taneda's experiments. To confirm the possibility of the existence of this negative Magnus force on the table tennis game, the wind tunnel test was conducted. As the result, it was observed at Reynolds numbers higher than 5.35 × 10^4. And we also provide a simple approximation of the lift and drag force to simulate a motion under the condition affecting a negative Magnus force.