Abstract:When the angle of attack exceeds the critical value during flight of aircraft, the air flow attached to the upper surface of the wing begins to separate in a large area. At this time, the lift coefficient decreases with the increase of the angle of attack, which is called stall. When the plane stalls, the control is greatly affected so it is a dangerous flying condition. During the test flight of a civil regional jet, it was found that stall characteristics were mainly affected by rolling stall, and unacceptable stall characteristics appeared before the maximum lift coefficient was reached. In the stall entering process, aileron control efficiency decreased rapidly, and the aircraft rolled sharply when approaching stall. Vortex generators are widely used in civil aircraft, which can improve the flow separation of wings and thus improve stall characteristics, and have the advantages of small modification and high feasibility. In this paper, the stall characteristics of a regional jet were improved by installing vortex generators on the upper surface of the wing. The position, height, deflection angle and quantity of vortex generator were designed by numerical calculation. Through low speed and high Reynolds number wind tunnel test, the actual effect of vortex generator was verified. Finally, several effective schemes of vortex generator were obtained.