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

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