Drag Reduction and Directional Control of a Projectile Using Plasma Actuators

High-speed projectiles experience flow separation at their blunt downstream end. Previous research has demonstrated the ability for plasma actuators to prevent flow separation as well as to vector a flow around a surface radius. A projectile model with a varying radius on the downstream end was experimentally examined between free-stream Mach numbers of 0.3 to 0.5 to determine the ability of plasma actuators to lower the aerodynamic drag, and to provide asymmetric aerodynamic loading that could be used for flight control without moving surfaces. This involved an annular plasma actuator that was located at the aft end of the projectile model. The aft end of the model was removable to allow for different radii edges. For drag reduction, the plasma actuator encircled the entire circumference of the aft end of the projectile. For asymmetric loading, the plasma actuator circled only half (180 degrees) of the circumference. Both arrangements were able to affect the aerodynamic loading on the projectile. The full annular plasma actuator provided a maximum drag coefficient reduction of 5%. The half-annular actuator provided a change in the side-force coefficient of 0.08.