Wind tunnel testing of scaled models of a newly developed Darrieus-style vertical axis wind turbine with auxiliary straight blades. (15th December 2016)

• Record Type: Journal Article
• Authors: Scungio, M.; Arpino, F.; Focanti, V.; Profili, M.; Rotondi, M.
• Is Part Of: Energy conversion and management. Volume 130(2016)
• Page Start: 60
• Page End: 70
• Publication Date: 2016-12-15
• Subjects: Darrieus-style wind turbines -- Power coefficient -- Torque coefficient -- Static torque coefficient -- Wind tunnel -- Tip speed ratio; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2016.10.033
• Languages: English
• ISSNs: 0196-8904

Abstract

Highlights: Wind tunnel investigations of Darrieus-style VAWT with auxiliary blades have been made. Results have been compared with those from standard Darrieus VAWT. Static and dynamic power and torque coefficients were measured and evaluated. The auxiliary airfoils have demonstrated to give more torque at the lower wind speeds. The proposed VAWT configuration is able to work in a wide range of wind speeds. Abstract: Renewable sources of energy, needed because of the increasing price of fossil derivatives, global warming and energy market instabilities, have led to an increasing interest in wind energy. Among the different typologies, small scale Vertical Axis Wind Turbines (VAWT) present the greatest potential for off grid power generation at low wind speeds. In the present work, wind tunnel investigations about the performance of an innovative configuration of straight-blades Darrieus-style vertical axis micro wind turbine, specifically developed for small scale energy conversion at low wind speeds, has been made on scaled models. The micro turbine under investigation consists of three pairs of airfoils. Each pair consists of a main and auxiliary airfoil with different chord lengths. A standard Darrieus configuration, consisting of three single airfoils, was also tested for comparison. The experiments were conducted in a closed circuit open chamber wind tunnel facility available at the Laboratory of Industrial Measurements (LaMI) of the University of Cassino and Lazio Meridionale (UNICLAM). Measured data were reported in terms of dimensionless power and torque coefficients for dynamic performance analysis and static torque coefficient for static performance analysis. The adoption of auxiliary airfoils has demonstrated to give more dynamic torque at the lower wind speeds with respect to a standard Darrieus rotor, resulting in better performance for all the wind speeds considered. In terms of dynamic power coefficient, the standard Darrieus configuration presented slightly better performance for the highest wind speed analyzed. The proposed configuration showed also an higher value of static torque coefficient with respect to the standard Darrieus micro turbine, resulting in a better self-starting ability.