Vertical axis wind turbines (VAWTs) are promising for urban applications due to their ability to operate in turbulent flows. However, the poor self-starting capability of Darrieus turbines and the low efficiency of Savonius turbines at high tip speed ratios remain significant challenges. In this study, a new hybrid wind energy system based on combining the two aforementioned rotors, has been proposed. The Darrieus rotor has been improved by J-type airfoil and the Savonius rotor has been enhanced by airfoil section instead of bucket or circular section. The aerodynamic performance of this novel hybrid VAWT, consisting of a J-type Darrieus rotor (based on NACA 0021) and bulk airfoil equipped Savonius rotor (with FX74-CL5-140 section), is numerically investigated. Two-dimensional unsteady simulations are performed using ANSYS Fluent with the SST k-ω turbulence model. The parameters being studied are 2-blade and 3-blade Darrieus configurations and the radial gaps (G=0.03m=0.15RS and G=0.06m=0.3RS) between the rotors in terms of the Savonius rotor radius. Qualitative and quantitative assessment have been performed based on the Cm and Cp indices and also the pressure, velocity, and vorticity countours. The results indicate that the three-blade configuration with a radial gap of 0.03m (0.15RS), yields the best performance, achieving a peak power coefficient of approximately 0.46 at a tip speed ratio of 2.5, which represents a significant improvement over the conventional hybrid design. Analysis of velocity and pressure contours reveals that reducing the radial gap, would enhance the aerodynamic interaction between the two rotors, leading to increased torque and power. Another side effect of using this hybrid configuration would be torque fluctuation reduction which was revealed in the moment diagram. Overall, the presented numerical study could be a assumed as a baseline for both design approach and geometric optimization in the field of small or medium scale hybrid vertical axis wind turbines.