Experimental and Numerical Investigation of the Control of the Flow Structure on Surface Modified Airfoils

In this study, experimental and numerical flow analysis was performed on three different blade profiles with a chord length of ۱۶۵ mm using passive flow control method. The first of the airfoil is the standard NACA ۰۰۱۸ profile. The second airfoil type has a NACA ۰۰۱۸ profile with a gap in the suction surface. The last airfoil is the NACA ۰۰۱۸ profile which is ۶۶% of the trailing edge cut from the chord length. All airfoil profiles were analyzed at the Reynolds number, Re=۲x۱۰۴, and angles of attack α=۰o, ۵o, ۱۰o, ۱۲o and ۱۴o in both experiment and numerical studies. The experiments were carried out using the Particle Image Velocimetry (PIV) method in a closed-loop open water channel, and the time-averaged velocity vectors, streamlines, and vorticity contours of the flow field were obtained. Subsequently, numerical analyses were performed using the ANSYS Fluent package program, one of the Computational Fluid Dynamics (CFD) programs used frequently in the literature. The streamlines and pressure contours of the airfoil profiles have been compared visually at the same Re and different angles of attack. In addition, according to the angle of attack of the airfoil profiles, lift coefficient CL, drag coefficient CD, and the ratio of lift coefficient to drag coefficient CL/CD graphs were presented. It has been shown that the gap on the airfoil at high attack angles caused changes in lift (up to ۰.۷) and drag (up to ۰.۱۵). These features can allow these models to be used for different purposes in the aerodynamics field.

Keywords:

PIV , CFD , Airfoil , NACA ۰۰۱۸ , Passive flow control