Optimizing NACA Airfoil Thickness Function Parameters for Maximum Lift-to-Drag Ratio

摘要

Since their inception nearly a century ago, the NACA family of airfoils have been used extensively in all types of applications. The way a NACA airfoil is constructed depends on a few parameters, such as the location of the maximum camber, for example, and a number of functions that describe the various surfaces, such as the mean camber line and the thickness functions. These functions have gone unaltered since the NACA airfoils were first designed. In this work, we use genetic algorithms to optimize the coefficients of the thickness function that describe the thickness of the upper and lower halves of the airfoil, above and below the mean camber line. The goal of the optimization is to maximize the lift-to-drag coefficient. The process is tried for a Reynolds number representative of the flow conditions of a typical midsize jetliner at typical cruising conditions. Two different angles of attack were tested. COMSOL Multiphysics was used to provide the fitness values for the various designs. It is shown that appreciable improvements in the lift-to-drag coefficients ratio were possible for many famous airfoils. The methodology could be used to carry out further optimization studies of many parameterized shapes for many different applications.