Static stall alleviation using a rail plasma actuator

Abstract

An experimental study was conducted to investigate the ability of a rail plasma actuator (RailPAc) to alleviate static stall on an airfoil. The RailPAc device consists of parallel rails flush mounted on the upper surface of a VR-12 airfoil, with a high-current (∼1.3 kA) arc bridging the gap between the rails. A Lorentz force (∼0.3 N lasting ∼1 ms) generated on the arc propels it along the airfoil chord and transfers momentum to the surrounding flow. Experiments were conducted in a low speed wind tunnel at two different Reynolds numbers ( and ) and various static angles of attack (up to ∼30°). Particle image velocimetry (PIV) was used to measure the flow over the passive and actuated airfoil, while the airfoil lift was measured using a force balance. The experiments showed that the RailPAc promotes flow reattachment and can suppress static stall over a wide range of angles of attack. Operation of a single RailPAc resulted in ∼40 improvement in post-stall lift and ∼4° increase in stall angle compared to a passive airfoil with an unpowered RailPAc. The results provide insight into the actuation mechanism and demonstrate, for the first time, the ability of the RailPAc to alleviate static stall on an airfoil.

Study of the dynamic behavior of the rail plasma actuator arc

“…Tracking the movement of turbulent eddies through the jets using high speed imaging make it clear that they are generating flow velocities ∼ 100 m s −1 . PIV and focusing schlieren measurements of the flowfield around the arc have been made in other work, however, more accurate measurements of flow velocity within the arc are difficult due to destruction of tracer particles by the high temperatures within the arc [23,24]. The column rests in between the jets and extends from 1-2 mm to 2 cm above the RailPAc sur face.…”