Wind energy is one of the oldest kinds of energy source used by mankind and it is dating back to thousand years. At the beginning of twentieth century, multi blades wind turbines were improved and used for charging in USA. After oil crisis in in the seventies, there was a surge of alternative energy sources in USA, Denmark and Germany. In terms of installed capacity, Germany had the leadership until 2007, then it passed to USA and finally China becomes the leader. Today, 6 MW capacity wind turbine are available in the market. The majority of the airfoils in use on horizontal-axis wind turbines today were originally developed for aircraft but it has been begun to design airfoil especially for wind turbine for 20 years. S series airfoil poses the most significant examples designed by NREL. In this study, S809 airfoil was simulated using the SST turbulence model and compared with experimental data to validate simulation accuracy of the computational fluid dynamics and this calculation. After verifying the consistency of the simulation model, S830 airfoil was simulated with different Reynolds numbers or velocities. Lift and drag coefficient, lift to drag ratio and pressure coefficient were calculated and compared