Wake-Fin Tailoring for Projectile Steering

Proof-of-concept experiments and computational simulations were conducted to investigate the feasibility of an active flow control concept, called wake-fin tailoring (WaFT), to improve the steering performance and attitude control of projectiles. The concept is based on the use of mechanical flow control actuators located at a position well upstream of the projectile’s tail. With an asymmetric deployment of the actuators, the system induces an asymmetric wake-flow that interacts with the tail fins to generate aerodynamic control forces and moments. Low-speed wind tunnel experiments were performed on a representative surrogate tank munitions (STM) model. In addition, CFD modeling and simulations for the projectile were carried out at subsonic and supersonic speeds to investigate the flow control mechanism and determine the control performance at operational flight speeds. Results from wind tunnel measurements and CFD simulations conducted at low angles of attack demonstrate generation of lift force and pitching moment by the WaFT, which can be used to provide in-flight adjustment capability, reduce dispersion and increase endgame maneuver footprint of the projectiles. The control authority can be enhanced by optimizing the locations and sizes of the control actuators.