This paper studies the effect of some shape parameterization techniques on automatic two-dimensional
aerodynamic shape optimization using the discrete adjoint method. In this paper, the Hicks-Henne Bump
Functions (HHBF) technique and the Free-form Deformation (FFD) control points technique are used to
parameterize the shape of the NACA 0012 airfoil. First, this paper makes a full detailed description of the
shape optimization workflow, including Euler equations, geometry parameterization techniques, discrete
adjoint method, gradient evaluation, optimization algorithm, and mesh deformation. Second, it explores how
shape parameterization techniques are implemented in the optimization problem. Finally, the results are
evaluated to compare the efficiency of mentioned techniques. The results suggest that, in general, both
techniques were shown to be equivalently effective as geometry parameterization method for shape
optimization problem. However, it appears that the HHBF technique demonstrates better performance with
less design iterations compared to that of FFD technique. In the other hand, FFD shows stability and a
smoother decrease in drag values, while HHBF exhibits greater unsteadiness during the optimization process.
