Computational Analysis of Darrieus Vertical Axis Wind Turbines for Exhaust Air Energy Extraction

In the last few decades, the need for research and implementation of various renewable energy technologies has been amplified due to the depletion of fossil fuel sources and greenhouse gas emissions. With the advancement of technologies, wind energy has been proven to be one of the most promising renewables, green and sustainable energy technologies among the alternatives. Several research investigations are being conducted for open-air conditions; however, studies on guided and restricted airflow conditions, such as exhaust air energy extraction, are minimal. Vertical axis wind turbines (VAWT), particularly lift-based Darrieus turbines, could be a good solution with its low-cost solution for the confined area of applications. This study conducted a three-dimensional numerical analysis of the Darrieus VAWT with the S1046 airfoil in the H-Darrieus and helical VAWT configurations. The finite volume-based Ansys Fluent software package has been used with the Shear stress transport (SST) k-ω turbulence model to solve the implicit unsteady Reynolds-Averaged Navier–Stokes equations. The performance of Darrieus turbines has been calculated in terms of power coefficients and torque coefficients. In this study, the numerical analysis has presented the Darrieus turbines as one of the efficient alternatives to extract energy from exhaust air applications. The maximum power coefficients of 0.39 and 0.351 were found for the H-Darrieus VAWT and the helical Darrieus VAWT, respectively.