Ground effect on the aerodynamics of a naca 0015 airfoil with a plain trailing-edge flap

Abstract

The ground effect on the aerodynamics of a NACA 0015 airfoil with a plain trailing- edge flap was investigated experimentally at Re = 1.61 × 105 . The ground proximity led to an increased lift and nose-down pitching moment compared to their out- of-the-ground effect counterparts. The flap deployment also caused the flow separation to move further upstream, rendering to an earlier stall as the ground was approached. The amount of lift increment was, however, found to be most significant at low angles of attack and was reduced with increasing trailing-edge flap deflection. Meanwhile, the pressure drag of the flapped airfoil was reduced in ground effect. The enhanced aerodynamics of the flapped airfoil, especially in close ground proximity can greatly benefit the take-off and landing of WIG (wing- in-ground effect) craft.