Effect of Airfoil Thickness on Flow Over the Symmetric Airfoils: Part I-Experimental Analysis

This study is an experimental study for NACA 0012, NACA 0015, and NACA 0018 airfoils at different angles of attack and low Reynolds numbers. The used experimental techniques were oil-flow visualization and force measurement. In the oil flow visualization experiments, low Reynolds number flow phenomena such as laminar separation bubble, separation, and reattachment were determined on the airfoil surfaces. The length of the LSB decreased and it moved towards the leading edge of the airfoil as the Reynolds number and the airfoil thickness increased. The force measurement results illustrated that as the Reynolds number raised, the stall angle was delayed. At the same Re number, aerodynamic performance raised with the increase in the thickness of the symmetrical airfoil, but due to the trailing edge separations, the performance decreased for the NACA0018 airfoil.