Aerodynamic drag crisis and its possible effect on the flight of baseballs
作者:
Cliff Frohlich,
期刊:
American Journal of Physics
(AIP Available online 1984)
卷期:
Volume 52,
issue 4
页码: 325-334
ISSN:0002-9505
年代: 1984
DOI:10.1119/1.13883
出版商: American Association of Physics Teachers
关键词: drag;aerodynamics;reynolds number;boundary layers;turbulence;trajectories;spheres
数据来源: AIP
摘要:
At Reynolds numbers above about 105the aerodynamic drag force on a sphere drops sharply as the flow begins to become turbulent in the boundary layer. For baseballs, this ‘‘drag crisis’’ may occur at speeds which are typical for pitched or batted balls. The effects of the drag reduction on the behavior of both pitched and batted balls is significant, and may explain several features of the game of baseball which previously have been unexplained or attributed to other causes. In particular, the drag reduction may help to explain why pitched fastballs appear to rise, why pitched curve balls appear to drop sharply, and why home run production has increased since the introduction of the alleged ‘‘lively ball.’’ Calculations suggest that aerodynamic forces are as important a factor in fastpitch softball as in baseball, and that they are a critical factor in a number of other ball games.
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