Design And Optimization Of Two-element Airfoil

Performance of high-lift system become more and more important in nowadays with commercialtransports traveling in much higher velocity. The Fowler-type flap provides higher lift increment thancommon single slotted flap, and it is more simple than double slotted flap and triple slotted flap instructure and motion mechanism, which makes it easier to optimize the lift of flap.Sharp of flap is segmented into three and modeled with conic curves. Flow field of thetwo-element airfoil is simulated by SST-k-ω turbulence model in ESI-CFD. Lift coefficient of thetwo-element airfoil is enhanced through three steps, increasing chord length and angle of flap,optimizing flap gap, and modifying sharp of flap.3D aerodynamic grid of the wing with flap ismodeled and flow field of the wing is simulated in the end.The result of study shows that, the lift coefficient of two-element airfoil increases significantlywith increasing chord length and angle of flap, the max lift coefficient is enhanced effectively byoptimizing gap parameters and changing shape of flap. In the gap parameters optimization phases,serious flow separation occurs at the upper of flap, because wake flow of main airfoil element can’tinhibit the separation when attack angle of two-element airfoil is too small. When attack anglebecomes bigger, distance of main airfoil and flap decreasing in the direction of free stream, inhibitionof main foil’s wake flow is effective enough to control the flow separation.