3D shape synthesis of Vertical Axis Wind Turbine blades for specified wind distribution and tip speed ratio

Ivo Marinić-Kragić - FESB

CHALLENGE Recently increasing demands for renewable energy solutions have resulted in an increase in the popularity of small Vertical-Axis Wind Turbines (VAWT). The aim of this paper is to develop a workflow that can develop a VAWT blade shape for both wind speed distributions and TSR (tip speed ratio) limits. The diversity of VAWT shapes illustrates that an optimal solution still does not exist. The goal is to find an optimal shape for a specified location, with defined TSR by using generic surfaces. 

SOLUTIONThis paper uses computational fluid dynamics (CFD) due to results that compare favorably with experimental data. The objective is maximal energy with limited TSR. The developed computational framework synthesizes a shape that is a sort of TSR based compromise between the advantages of both Darrieus and Savonius design, adapted to local wind speed distribution. The shape parameterization is achieved by a B-spline surface based shape parameterization developed specifically for VAWT design.

BENEFITS ​- The numerical workflow integrated with modeFRONTIER steers the shape of VAWT blades based on the input wind speed distribution and TSR limits. The procedure resulted in different shapes, thus allowing a compromise between small TSR and better energy conversion efficiencies.