Study on Flow Mechanism and Aerodynamic Characteristic of High-Lift Devices with Drooped Spoiler

Taking advantage of computational fluid dynamics, the simulation of two-dimensional and three-dimensional high-lift devices with deflection of spoiler or not was done.The flow mechanism and aerodynamic characteristic of high-lift devices landing configuration with drooped spoiler were studied. The result indicated that the aerodynamic performance of the landing configuration can be improved when the spoiler deflected and the parameters of the gap and overlap were kept constant compared with the initial configuration, the lift coefficient of the linear section at the same angle of attack significantly increased, and the maximum lift coefficient also increased; When the spoiler deflection angle increased to 10°, the linear section of the lift coefficient moved up about 0.2 and the maximum lift coefficient increased by about 4.2%. The analysis of the flow mechanism showed that: on the one hand, the camber and circulation of the main wing can be enhanced by the deflection of spoiler, and the washing effect on the slat and the flushing effect on the flap were enhanced, as a result, the lift of main wing and slat increased and the lift of flap decreased, which was reflected in the increase of the total lift; on the other hand, deflection of spoiler is helpful to enhance the Coanda effect of the slotted jet and improve the speed of the upper surface of the flap, resulting in delaying the emergence of the separation zone and restraining the decrease of the flap lift.