Abstract
The dynamic behavior of a sports ball has a close relationship with fluid dynamics. The seams and/or dimples on the ball surface affect the lift and side forces as well as the drag as it flies through air. This often causes erratic flight paths. In the case of baseball, a slowly rotating ball also manifests this behavior. It is believed that this is caused by the flow separation that occurs asymmetrically over the baseball. In the present experiment, the characteristic of the force acting on a baseball is measured with a load cell and the flow field at and behind the seams of the baseball is visualized with a smoke-wire technique. Three-dimensional wake patterns associated with various ball and seam orientations were identified.
