A CFD parametric investigation on velocity increment induced by an empty diffuser with circumferential holes for horizontal axis wind turbine applications

This study examines the optimal parameters for augmenting a DAHAWT through a CFD analysis. Previous literature has looked into using diffusers to increase wind turbine energy generation, although the impacts of the surface of the diffuser, flange angles, and the interactive effects of all related angles were not fully taken into account. The current research primarily focuses on examining the impacts of the diffuser with circumferential holes and flat surfaces of diffusers, flange angles (0°, ,10°, 15°, and 20°), flange surfaces of the diffuser, the interactive effects of the opening angles, and all related angles for a wind speed of 4.5 m/s. For the inlet shroud-flanged hole diffuser surfaces, the optimum velocity of 9.35 m/s for the inlet shroud angle of 24°, 8° opening angles and 0.3 flanges height-to-throat ratio were obtained. For the current study, an optimum increase in velocity of 107.77% compared with the intake velocity to the chamber. About an 8.97% increment in power was attained for the optimum power output. The optimal speed was recorded 0.175 meters away from the diffuser's inlet section, suggesting that this is where the turbine should be placed. The present research's numerical fluid dynamics findings were verified with results from the experimental literature, and the outcomes showed an acceptable standard of consensus among both of them. As a next step, the integration of the circumferential hole diffuser with wind turbine system simulation, economic analysis, and hands-on work with field testing are suggested.