A fin-stabilized projectile is usually designed to induce spinning motion by a canted/beveled fin design to suppress the effect of aerodynamic asymmetric perturbation on ballistic stability. Aiming at the problem that the initial spinning speed of the fin-stabilized projectile fired from a Recoilless rifle with Rifling jumps between 2000 and 3500 r/min, which may cause the ballistic dispersion, this study systematically reveals the spinning characteristics of the fin-stabilized projectile and its mechanism of the projectile dispersion by constructing the trajectory model of the fin-stabilized projectile, designing the spinning speed test system, and carrying out the equilibrium spinning speed theoretical analysis. Research results show that the initial spin speed of the projectile shows exponential decay near the muzzle, and all converge to a uniform equilibrium state at about 75 m. The effect of the initial spin speed difference on the ballistic dispersion is angle of attack dependent. When an angle of attack exists, the spin speed difference affects the projectile stability, which affects the course of the angle of attack motion, causing a change in the magnitude and direction of the aerodynamic forces applied to the projectile, resulting in a difference in the magnitude and direction of the velocity in the forward trajectory segment (x 75 m), and ultimately causing a dispersion of the projectile at the end of the trajectory.
Ding et al. (Fri,) studied this question.