Effect of changes in flap deflection and addition of slat clearance on aerodynamic performance of the wing airfoil NACA 43018 in the cruising and landing phases

The phase change from cruising to landing is one of the critical conditions in aircraft flight. The role of the control surface and high lift devices of the aircraft is the focus of attention in this condition because these components greatly affect the movement of the aircraft. In today’s commercial aircraft, flaps and slat clearance are always used on the wings so that they affect the movement and aerodynamic performance of the aircraft. Changes in the cruising and landing flight phases affect aerodynamic performance because the combination of flap and slat clearance changes. This research was conducted by numerical simulation on the NACA 43018 wing airfoil. The observed conditions were plain wing, slot, and flap which were compared with the use of slat slot and a flap in cruising and landing conditions. The angle of attack used is (α)=0o, 2o, 4o, 6o, 8o, 10o, 12o, 15o, 16o, 17o, 19o, and 20o. Numerical simulation using Ansys 19.1 application with turbulent model k-ε Realizable at velocity freestream of 120 m/s. Changes in the slat clearance and flap deflection elements from the cruise to landing phase cause a very significant change in aerodynamic performance. Flap δT = 0o which has the highest aerodynamic performance and a high stall angle is then converted to flap δT = 30o which has low aerodynamic performance and low stall angle according to the desired flight phase conditions. Induced drag has a large influence on the formation of the total drag of all configurations where the flap δT = 30o has the highest value. The use of slats increases the momentum of the flow to delay the separation and reduce the tip vortex effect. Keywords: slat clearance, cruising, NACA 43018, flap deflection, landing.