The family of NACA symmetric airfoil sees wide use in all general purposes. These geometries are usually conveniently generated by an airfoil plotter available online. However, sometimes it may be required that the shape of the airfoil to be defined by explicit mathematical equations, and can be modified directly by the adjustment of several control parameters which represent properties of the airfoil geometry of common interest, e.g. position of the thickest point along the chord, or thickness of the trailing edge. This article aims to present a set of formulae which, after the forward substitution of several control parameters, gives explicit equations of the airfoil curve.
The PDF file of this article is available here.
The NACA report No.492, which this article is based on, can be found here.