Use of Microspoilers for Control of Finned Projectiles

Abstract

Relative to other air vehicles, the physical control mechanism on a smart projectile plays much more of a central role in the overall system design. Many different smart projectile control mechanisms have been created, including aerodynamic based mechanisms such as movable canards, propellant based mechanisms such as squibs, and inertia based mechanisms such as internal moving masses. The work reported here considers small micro spoilers located between rear fins to create aerodynamic force changes to enable projectile control. In particular, boundary layer shock interaction between the projectile body, fins, and micro spoilers provides a multiplicative effect on controllable forces and moments. A parametric study varying the micro spoiler configuration is conducted to examine the level of control authority possible for this control mechanism concept. Results indicate that relatively small micro spoilers located between fins generate substantial control authority that is capable of eliminating impact errors caused by muzzle jump, aerodynamic uncertainty, and atmospheric winds. These conclusions are based on CFD predictions of the effect of micro spoilers on air loads coupled to a rigid 6-degree-of-freedom projectile trajectory simulation.