Abstract:
The shape of an airfoil is paramount to its aerodynamic characteristics. In many applications,
the streamlined shape has proven to be the most effective geometry shape. Airfoils are
employed in aircraft wings, tails, and other control surfaces, wind turbines, boats, and ships,
among other things. The current study compares the numerical aerodynamic performance of
two regularly used airfoils, NACA 0015 and NACA 4415. The study is to evaluate the
performance of these airfoils in terms of lift, drag, and lift to drag ratio at various angles of
attack using wind tunnel experiments and computational fluid dynamics (CFD) simulations.
These two airfoils were evaluated in a subsonic wind tunnel at Reynolds numbers ranging from
1×105 to 3.5×105. The NACA 0015 and NACA 4415 were tested from 0° to 18° angle of attack
with a 2° interval. The conventional Sparlat-Allamaras model is used in the computational
procedure. The outcome demonstrates a similarity between experimental and CFD results. The
lift and drag curves for both profiles follow the same pattern. The optimum angle of attack for
both airfoils is 14 degrees. However, the experimental results show that drag is greater,
particularly at higher angles of attack. Both airfoils are thick, which adds structural integrity
to the blades at the expense of increased drag. Furthermore, it has been shown that symmetric
airfoils offer no lift at 0° AOA, making them extremely useful in control surface applications,
whereas cambered airfoils provide higher lift, which is beneficial for devices requiring more
lift, such as wind turbines.
