Ballistics, 2nd Edition

352 Ballistics: Theory and Design of Guns and Ammunition

This relationship will produce a motion in exactly the same manner as the aerodynamic

jump developed in Section 12.1. It essentially couples the yawing motion of the projectile

to the swerving motion. Both will thus damp together and the more yaw, the greater the

epicyclic swerve.

If we examine the spin-stabilized projectile, we can write

M >

′′

0and

ψψ

1

2

2

2



(12.21)

With the aforementioned mathematical statements, McCoy [1] has stated that an excellent

approximation of Equation 12.15 for a spinning projectile is

Sk

C

C

Ki i

ET

L

M

spin

exp( )=−













′

′













+

′

2

1

2

20 20 2

α

α

ψ

ψ

ψλψ

exp[(

22

1)]s −

{}

()

(12