Aerodynamic Optimization of Microspoiler Actuators for Guided Projectiles

Abstract

Microspoiler actuators have been established as a viable control mechanism for gun-launched guided projectiles. Although the geometric configuration of the microspoilers is known to have a large impact on control authority, these geometrical dependencies have previously not been well characterized. This work seeks to derive an optimal microspoiler configuration that maximizes control authority. Parametric computational fluid dynamics studies are performed in which configuration parameters of the microspoilers are varied and the effects on control forces and moments quantified. Through an iterative approach, an optimal configuration is identified that maximizes the ratio of the control authority to the drag penalty. This optimal configuration exhibits twice the control authority of that used in previous studies. Further computational fluid dynamics simulations are performed to characterize the effects of the spoiler height, Mach number, and angle of attack. In addition, the effect of the spoiler interaction with static fins is quantified to explore the mechanism’s applicability to spin-stabilized projectiles. Trajectory simulations using the optimized geometry show that the microspoilers produce favorable control authority for supersonic fin-stabilized rounds. This control authority is shown to be similar to that obtained using canards, with the added benefit that the microspoilers can be easily retracted into the projectile body when not in use.