Bullet Turning at Trajectory Apex
Publication: Journal of Aerospace Engineering
Volume 27, Issue 5
Abstract
A numerical study is carried out to investigate a 7.62-mm bullet turning at the trajectory apex, particularly when fired vertically. The bullet model includes an aerodynamic model, which basically covers angles of attack up to 180°. Computational fluid dynamics are used to estimate the aerodynamic properties at the high angles of attack. The role of aerodynamic moment, and particularly Magnus phenomena, in turning at the apex is studied. A positive Magnus moment tilts the total aerodynamic moment vector clockwise and generally drives the bullet turning nose down. The bullet turning was detected through a flat spin–type maneuver. The Magnus-moment oscillatory behavior and/or the Magnus-moment-caused bullet instability may occur during the turning at the trajectory apex. These were found to have a negligible effect on the bullet-turning launch angle, but they may contribute considerably to the bullet falling-phase behavior. Possibilities to affect the bullet descending part of the flight are also shortly considered.
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Published In
Journal of Aerospace Engineering
Volume 27 • Issue 5 • September 2014
Copyright
© 2014 American Society of Civil Engineers.
History
Received: Oct 2, 2012
Accepted: Apr 22, 2013
Published online: Apr 23, 2013
Published in print: Sep 1, 2014
Discussion open until: Oct 16, 2014
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