An airfoil section with large camber adopts a single slot flap,whose gap has significant influence on lift characteris-tics,causing the change of the overall shape of lift curves.Research based on solving RANS equation shows that there are 5 areas with large variation of lift curve shape,which is mainly featured by the gap length between the flap and the upper main wing trail-ing edge.The areas are named as D,C,B,A,E as the distance goes from the nearest to the furthest.The A zone has the gap length between(1.01～1.33)％chord length,which shows the highest maximum lift coefficient and stall angle,and the lift curve slope is large with the value of 0.088(1/°).The fllow field analysis shows that in this zone the flow at the flap trailing edge sepa-rates locally at small angles of attack(AoAs),but it turns to attached flow at larger AoAs.When moving closer to the main wing there are B and C zone,where the flow attaches the flap at small AoAs,generating larger lift increment at medium and low AoAs,but less lift on flap at higher AoAs,and the lift curve slope can be as low as 0.036(1/°),with also lower value of maximum lift co-efficient and stall angle.The D zone is closest to the main wing,where the lift increment is lower and nonlinear.In the furthest E zone,the coupling between the main wing and the flap is weak,and the lift increment is lowest.
关键词
单缝襟翼/缝道/气流分离/增升/最大升力系数
Key words
Single Slot Flap/Gap/Flow Separation/Lift Enhancement/Maximum Lift Coefficient
维普
万方数据