This paper presents a numerical simulation of flow control over the S809 wind turbine airfoil using a rod as a passive flow control device at a Reynolds number of \(10^6\) . The rod is positioned near the leading edge of the airfoil at various locations on the suction side. The fluid flow around the profile is governed by the unsteady Reynolds-averaged Navier-Stokes (URANS) equations, which are solved in a two-dimensional domain using the ANSYS Fluent CFD software. The SST \(k\omega\) model is used to simulate the turbulence. The simulation results are first validated by comparison with data published in the literature. Then, the influence of the rod position on the aerodynamic characteristic of the profile is investigated. The results show that the rod reduces the separation zone and improves profile aerodynamic performance. For a 20° angle of attack, using a rod with a diameter of \(d/c = 0.01\) , positioned at ( \(H/c = 0, V/c = 0.04\) ), can increase lift by 22% and reduce drag by 5.5%, resulting in a 29% improvement in the lift-to-drag ratio.