Analysis of projectile stability in linear induction type electromagnetic launchers

In the operation of linear induction type electromagnetic launchers, the projectile, which is inside the barrel, is not supported by any means except air. Hence, the projectile can be off-centered from the drive coils' axis center by initial placement, vibration or any disturbance. If the projectile is centered, the radial forces around the projectile are balanced. However, if the projectile is off-centered, the radial forces around the projectile are not balanced and there exists a net transverse force due to this asymmetry.;It is desired that the projectile be restored to the balanced position by itself with minimum oscillation when the projectile is off-centered even in the worst case. The worst case condition is when the projectile is off-centered by the air gap distance.;In this study, the motion of the projectile dynamics is investigated, assuming that the projectile is off-centered by any reason. The methods of calculating the restoring force and its characteristics are discussed, the techniques for manipulating the set of forces are discussed and the resulting motions of these forces are analyzed. Finally, the experimental results are used to verify computer calculations.