Investigation on Aerodynamic Performance of Unsymmetrical Blade Profile by Experimental and CFD Analysis

Power generation through wind turbines (vertical axis wind turbines (VAWTs)) is gaining popularity day by day as it is clean, economic and eco-friendly, however efficiency of VAWTs is always a matter of concern. Aerodynamic efficiency can be improved by using different types of blade profiles, mostly they are categorized as cambered and symmetrical. Most of the researchers showed that the camber of an airfoil causes an increase in velocity and a consequent decrease in pressure of the stream of air moving over the airfoil due to the increase in velocity it gets the maximum coefficient of lift. The main aim of this study is to compare performance parameters like Lift coefficient Cl, Drag coefficient Cd and aerodynamic efficiency (Cl/Cd) for NACA 4415 and NACA 0021 experimentally and computationally. For experimental study subsonic wind tunnel is used and to study computationally Ansys fluent analysis system is used. The parameters varied in this study are flow velocity and angle of attack. It is noticed from the experimental result that the maximum value of lift coefficient is higher for NACA 4415 as compared to NACA 0021 and stalling occurs at 16° for NACA 4415 and 18° for NACA 0021. It has been found from computational result that k-ε is best-suited model among SST k-ω, standard k-ω and k-ε models.