Abstract The need for clean, sustainable and cost-effective energy sources leads to the installation of wind turbines with advanced technologies. One of the main parameters which govern the productivity of any wind turbine is its power generation capacity. The higher the incoming wind speed, the more the power generation, but the challenges faced by wind turbine is in low wind speeds. Hence, it becomes important to boost the efficiency of wind turbine with modified designs for lower wind urban regions. The prime objective is to boost the power production of a conventional two-bladed VAWT with the application of convergent-divergent type wind lens. Ansys CFX is employed for numerical analysis of flow around the rotor of straight bladed H-Darrieus turbine. Different turbulence models are analysed and SST k-ω model is well validated with experimental result. Power coefficient values are evaluated at a range of 0.5 to 3 tip speed ratios in both cases. Simulation result is validated with experimental results in terms of power coefficient. Computational result is validated with 4% error and 2% error for simple VAWT and VAWT with wind lens respectively. The results show an enhancement of 2.6 times the power coefficient values of conventional VAWT.