Criticism study of J-Shaped darrieus wind turbine: Performance evaluation and noise generation assessment

Vertical Axis Wind Turbines (VAWTs) are suitable for use in populated areas. The main parameter of the design of this type of the wind turbine is the cross sectional profile of the turbine blade. Additionally, the turbine performance and the generated aerodynamic noise of the VAWTs are critical issues that could limit the spreading of these turbines especially in the residential zones. In the last years, some publications investigated the J-shape Darrieus turbine and praised the performance of this design. Therefore, the present investigation introduces a criticism of the J-shape Darrieus Vertical Axis Wind Turbine (J-SD-VAWT) with three-bladed rotor. An accurate comparison has been introduced for three different turbines with different airfoils sections (NACA 0015, NACA 0021 and S1046). The comparison included the standard airfoil design and the J-shape of the same airfoils from two points of views of turbine performance and noise generation. Aero-acoustics and performance of the proposed design was thoroughly investigated using the Computational Fluid Dynamics (CFD). Both the Unsteady Reynolds-averaged Navier-Stokes (URANS) equations and the impermeable Ffowcs Williams and Hawkings (FW-H) equation were simultaneously solved. The effects of J-shape cut ratio, speed ratio, and turbine solidity were investigated. For all configurations, the results indicated that J-shape reduced the performance and did not reduce the turbine noise.