The Engineering of Sport 7 pp 429-436 | Cite as
Aerodynamics of a Curve-ball: The Sikorsky/Lightfoot Lift Data (P234)
Abstract
In the 1940s and 50s, the United States was engaged in a national debate on whether the curve in baseball was an optical illusion. During this debate, Igor I. Sikorsky and Ralph B. Lightfoot investigated the lift force produced by a baseball spinning from zero to 1200 rpm (revolutions-per-minute) in a wind tunnel at free-stream velocities between 80 and 110 miles per hour1 (35.8 and 49.2 m/s). A brief note about the findings were later published by Joseph Drury (1953) reporting Sikorsky had determined that a four-seam pitch could curve three time more than a two-seam pitch. However, the substantive supporting experimental data was never published and over the years appeared to have been lost. The Sikorsky/Lightfoot data set was rediscovered; it is compared to more recent aerodynamic lift data for golf and baseballs with excellent correlation. The data also shows that seam orientation (i.e. surface roughness) has a large influence on lateral deviation in a high velocity pitch.
Key words
Baseball Aerodynamics Lift CoefficientsPreview
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