NACA-ACR-3I20

Abstract

<strong>INTRODUCTION</strong> <br>The NACA has for some time been investigation airfoils equipped with high lift devices for the purpose of improving the performance characteristier these airfoils. The result of tests of low-drag airfoil equipped with plain, split, or slotted flaps have been obtained with large-drag airfoils equippod with plain, split, or slotted flaps have been presented in reference 1.The results of references 2 and show that, on conventional air-foils, the lightest lifts have been obtained with large-chord venation-blind and double-slotted flaps. The present investigation was made to determine the lift, drag, and pitching-moment characteristics of a low-drag airfoil with a double-slotted flap at various flap deflections. In addition, the optimum position for maximum lift and flap path were to be found.