Self-start evaluation in lift-type vertical axis wind turbines: Methodology and computational tool applied to asymmetrical airfoils

Abstract

The rapid growth of wind power generation and the need for a smarter electrical grid with a decentralized energy generation, especially in the urban areas, has increased the interest in vertical axis wind turbines (VAWT). The Darrieus type VAWT performance prediction is a very complex task, since its blades move around the rotor axis in a three dimensional aerodynamic environment that leads to several flow phenomena, such as, dynamic stall, flow separation, flow wake deformations and their natural inability to self-start. In the lift-type turbines the self-start incapability can be overcome with the use of several more or less complex solutions, being one of them the development of a blade profile capable of making the wind turbines self-start. Hence, this paper focuses on presenting a new methodology for fast development of new blade profiles, for self-start capable Darrieus type VAWT.