A short review of recent research activities for characterization of aerodynamic optimization of vertical axis wind turbines

There is a growing interest in wind energy harvesting in the built environment. Vertical axis wind turbines (VAWT) seem to represent an ideal candidate for this purpose due to their omni-directional operation. However, as a result of a comparatively small amount of research on VAWTs during the last decades they fall short of horizontal axis wind turbines (HAWT) with respect to aerodynamic efficiency. Therefore, more research is required in order to optimize VAWT performance. Several research methods including numerical modeling of varying complexity and large-scale wind tunnel measurements have aided the optimization of VAWTs. Designing new airfoils, finding the optimum solidity and tip speed ratio, blade fixed pitch angle, incoming flow Reynolds number and skewness angle and flow control are some of the adopted approaches to improve VAWT performance. The current study intends to present a short review of conducted research and propose new directions for future research.