MAGNUS AND DRAG FORCES ACTING ON GOLF （马格努斯和拖拽力高尔夫球）.pdfVIP

Colloquium FLUID DYNAMICS 2007 Institute of Thermomechanics AS CR, v. v. i., Prague, October 24 - 26, 2007 p. 1 MAGNUS AND DRAG FORCES ACTING ON GOLF BALL A. Kharlamov, Z. Chara, P. Vlasak Institute of Hydrodynamics AS CR, v.v.i., Prague Abstract The paper describes the results of experiments with a rotating golf ball moving quasi- steadily in calm water. The motion of the ball was recorded on a digital video camera. The Cartesian coordinates and the angle of rotation of the ball were determined from the records of motion. The dimensionless drag force coefficient, Magnus force coefficient and translational and rotational Reynolds numbers were calculated from the time series of the ball coordinates and the angle of rotation for each recorded frame. The calculated data were averaged over rectangular cells on experimental domain on the plane of 4 4 translational and rotational Reynolds numbers, i.e. 1.2 · 10 Re 1.6 · 10 and 3 4 3.8 · 10 Reω 2.7 · 10 . Introduction The investigation of aerodynamic forces on rugged spheres is mostly connected with ball games. In such games as baseball, golf, football, and cricket, the lateral deflection of a rotating ball is of great interest for the player. In golf the rotation of the ball allows to obtain the higher and longer trajectories; in football the spinning of the ball allows to score from zones, from which it would be impossible to score without spinning. The lateral deflection of a ball is caused by the lateral force due to simultaneous rotational and translational movement. The force is known as Magnus force. The