Ballistic Studies of the Rotational Motion of the Artillery Projectile into Account the Equatorial Damping Moment

Abstract

The problem of calculating the equatorial damping moment during trajectory flight is an actual problem in
ballistic studies of the rotational motion of artillery projectiles. The practice of ballistic research needs short algorithms
that make it possible to calculate the damping moment together with the calculations of the trajectory parameters
under conditions of continuously changing characteristics of the oncoming flow. In this regard, a simplified method
for calculating the equatorial damping moment of artillery projectiles in the oncoming flow is proposed, based on
the differentiation of the dependence for the overturning aerodynamic moment by the angle of attack and the Mach
number of the oncoming flow. Calculations of the parameters of the rotational motion of the 155-mm artillery
projectile on the flight trajectory have been carried out. The influence of the equatorial damping moment on the
periodic components of the angular displacements of the projectile is revealed. The results of ballistic calculations
with the loss of stability of the rotational motion of the projectile showed the destabilizing effect of the equatorial
damping moment on the boundary parameters in terms of stability in the case of opposite directions of rotation of
the projectile and crosswind.