This work introduces a numerical analysis of three-bladed Darrieus vertical axis wind turbine performance using 25 different sectional profile airfoils from different families. This investigation is to optimize and maximize torque output coefficient and output power coefficient as well as studying force analysis for the optimum airfoil. Aerodynamic simulations were used depending on finite volume analysis using computational fluid dynamic (CFD) methodology. These CFD simulations used the unsteady (transient) Reynolds-Averaged-Navier-Stokes (URANS) calculations to solve and analysis the flow field around the turbine. Quantitative and qualitative validations were presented in this work, it is found that an acceptable agreement between the current CFD calculations and the published experimental work in the calculations of the power output coefficient. The results presented that the optimal configuration is LS (1)-0413 airfoil. The power coefficient of the turbine consists of LS (1)-0413 airfoil has been increased by 16% compared to NACA 0021 performance. Furthermore, in the current study, the different forces on the different elements of the Darrieus turbine were analyzed during the rotation as well as in stationary conditions for the best blade profile. (C) 2019 Elsevier Ltd. All rights reserved.