This paper investigates the performance of controlling Co-Flow Jet (CFJ) on NACA 0025 airfoil at five different Reynolds numbers of 5 • 10 4 , 7.5 • 10 4 , 10 5 , 1.5 • 10 5 , and 3 • 10 5 . To conduct the numerical solution of the fluid flow, 2D incompressible and unsteady Reynolds--averaged Navier-Stokes equations are solved using the SST-k-ω turbulence model. At all investigated Reynolds numbers, the lift coefficient enhances as the momentum coefficient increases, and its best performance is obtained at an angle of attack of (AoA) 15 • . It is also observed that using the CFJ is of greater importance at Re 10 5 than in other investigated cases.