The effect of slat clearance and flap on the aerodynamic performance of the NACA 43018 wing in the landing process

Combining several high lift devices on airplanes is a natural thing. High lift devices are used to control aircraft movements and improve aerodynamic performance. The landing phase in flight is vulnerable and requires good control, especially aircraft wing control that uses high lift devices. High lift devices such as slat clearance and flap are commonly used, but variations in their geometry always produce different and interesting phenomena to be explored further. This research was conducted numerically on a rectangular wing with NACA 43018 airfoil. This study will compare the rectangular wing with a wing that uses a combination of slat slots (slat clearance) and flaps on the landing process. The angle of attack used in this study is (α) = 0°, 2°, 4°, 6°, 8°, 10°,12°,15°, 16°,17°,19°, and 20°. Ansys 18.1 software with k-ϵ Realizable turbulent model is used to help the numerical simulation. The combination of slat clearance and flap results in a higher total drag coefficient and higher lift coefficient. However, the rectangular wing produces better aerodynamic performance. Visualizing the velocity path line and wall shear stress shows that the rectangular wing is easier to separate than the combined flap δT = 30° and slat δL = 0°.