Computation of the roll characteristics of a long L/D finned projectile and comparison with range data

Abstract

A recently developed computational technique has been applied to predict the aerodynamic roll characteristics of the M829 kinetic energy projectile. These aerodynamic parameters include the roll producing moment, the roll damping moment, and the equilibrium spin rate, defined as the spin rate for which the net roll moment is zero. These aerodynamic parameters have been determined by computing the flow field about the projectile using a parabolized NavierStokes computational approach. The computations have been performed using a rotating coordinate frame which rotates at the spin rate of the projectile. Comparison is made with results obtained experimentally from range firings and from engineering estimation approaches. The computed equilibrium spin rate and the spin histories agree well with the data obtained from range firings.