Effect of Single Slat and Double Slat on Aerodynamic Performance of NACA 4415

Abstract

This study uses a Computational Fluid Dynamics (CFD) approach. The main object in this study is NACA 4415 with slat variations. The airfoil used as the slat is Eppler 421. Reynolds number in this study is 3 Í 10 6 . This study uses an unstructured mesh with a triangular cell shape with 137824 elements. The use of slats can improve the aerodynamic performance of NACA 4415. NACA 4415 without slat stalled at AoA=16º. Stall on airfoils with a single slat and double slat occurred at AoA=20º. Slat can increase C l in NACA 4415; however, the difference in C l increase is not much different when using a single slat or double slat. An airfoil with a single slat, on average, can increase C l by 20.9129%. The average increase in C l for an airfoil with a double slat is 25 . 6878%. Single slat and double slat increase C d . A single slat increased C d with an average increase of 26 . 1109%, and the average increase in C d for airfoils with double slat was 54 . 6152%. Single slat can produce a better C l to C d ratio than double slat, but the optimum AoA of double slat is 1º higher than single slat. Visualization of fluid flow at AoA=16° shows the fluid flow separation in the airfoil without a slat. The fluid flow separation can be handled well when NACA 4415 is given a single slat or double slat .