# The Joukowski Mapping: Airfoils from Circles

The Joukowski Mapping: Airfoils from Circles

A simple way of modelling the cross section of an airfoil (or aerofoil) is to transform a circle in the Argand diagram using the Joukowski mapping, . The map is conformal except at the points , where the complex derivative is zero. You can drag the circle's center to give a variety of airfoil shapes, but it should pass through one of these points and either pass through or enclose the other. In this Demonstration, a good result may be obtained by dragging the center of the circle to the red target at .

f(z)=z+1/z

z=±1

(-0.2,0.2)