Aérojoules project: Vertical Axis Wind Turbine

Abstract

Recent years have seen more focus on the development of small and medium sized wind turbines aimed to urban or remote areas. For this reason, the vertical axis wind turbines (VAWTs) present an attractive alternative to the traditional horizontal axis wind turbines (HAWTs) in the environment of fluctuating wind. Particularly in France, the intention is to increase the proportion of energy produced by means of both on-shore and off-shore wind farms, including the development of small generators that can be used as power supply for remote residences, ships, or any residence in urban areas in order to reduce the consumption from the general power grid. This served the basis for the development of a series of VAWTs in the framework of the A´erojoules Project for the Nantes region. This work is oriented to the study and development of a small VAWT, with a specific focus on its aerodynamic and structural optimization, in order to maximize the power extracted from the wind. A design loop is presented, detailing the procedure for a decoupled fluidstructure analysis. Two main pillars of the design process are, therefore, the aerodynamic and the structural analysis. In relation to the aerodynamic design, a preselection of design alternatives for the turbine is carried out and a series of simplified CFD simulations are performed in order to define candidate solutions for detailed CFD models. With respect to the structural analysis, a simplified method to estimate the pressure loads on the blades for preliminary verifications is presented and its results are compared to those of available three-dimensional CFD simulations. A general discussion on the structural design of the blades is introduced, setting the basis for further work in this aspect. Finally, conclusions and recommendations are presented, as well as suggestions about future work related to the project.