| dc.description.abstract | Among the multiple techniques used for boundary-layer control and flow separation delay, moving surface boundary-layer control is one of the promising approaches. Adding a rotating cylinder is one means of enhancing the aerodynamic performance of an airfoil, given that it serves to be an effective way in delaying stall. In this study, a rotating cylinder has been embedded in the leading edge of a NACA0024 airfoil. The wing model has been analyzed experimentally as well as numerically. The airfoil has been tested experimentally in a subsonic wind tunnel under different angles of attack, 𝛼, and cylinder-to-freestream velocity ratios, 𝜁. The effect of both parameters on the aerodynamic performance has been investigated, mainly through calculation of the lift coefficient, 𝐶𝐿, the drag coefficient, 𝐶𝐷, lift-to-drag ratio, 𝐶𝐿/𝐶𝐷, and stall angle of attack, 𝛼𝑠𝑡𝑎𝑙𝑙. Additionally, flow visualization has been carried out to get a perspective on the behavior of the rotating cylinder. Multiple photos have been captured where the streamlines of the flow are clear to the eye. A 2D numerical simulation using Computational Fluid Dynamics (CFD) has been carried out using ANSYS FLUENT 17.0 software. Through replicating the exact conditions of the experimental work, the CFD simulation has been successfully validated by its experimental counterpart. Results have shown a promising increase in the maximum lift coefficient from 0.98 at 𝜁= 0 to 1.45 at 𝜁= 6, which translates to around a 48% increase. The corresponding stall angle of attack has increased simultaneously from 𝛼=15° at 𝜁= 0, to around 𝛼=35° at 𝜁= 6. This increase of lift, however, is accompanied by a 47% increase in maximum drag coefficient. Furthermore, varying the cylinder exposure between 20% and 40% has shown an increase of 6.6% to 19.6% in the lift coefficient at 𝛼= 10° and 20°, respectively. | en_US |
