Airfoil Stall Suppression by Use of a Bubble Burst Control Plate

To suppress the stall on an NACA 0012 airfoil, a thin plate (hereafter referred to as a burst control plate) was attached on the airfoil to delay the burst of laminar separation bubbles formed at the stall angle. The burst control plate is used to enhance the vortical structures in the separated shear layer. Wind-tunnel tests were conducted at a chord Reynolds number of 1.3 x 10(5). Flow visualization tests and surface pressure measurements showed that the burst control plate placed on the airfoil suppresses the bubble burst at a wide range of angle of attack and therefore, both the stall angle and the maximum lift coefficient are increased. The particle image velocimetry measurements indicated that when the angle of attack of the airfoil with the burst control plate is set higher than the stall angle of the original airfoil., a similar flow structure of the original airfoil was observed.