Computational aerodynamic optimisation of vertical axis wind turbine blades

Abstract

The approach and results of a parametric aerodynamic optimisation study is presented to develop the blade design for a novel implementation of a vertical axis wind turbine. It was applied to optimise the two-dimensional cross-sectional geometry of the blades comprising the turbine. Unsteady viscous computational fluid dynamic simulations were used to evaluate blade performance. To compare geometries, the non-dimensional coefficient of power was used as a fitness function. Moving meshes were used to study the transient nature of the physical process. A new parameterisation approach using circular arcs has been developed for the blade cross sections. The optimisation process was conducted in two stages: firstly a design of experiments based response surface fitting was used to explore the parametric design space followed by the use of a Nelder–Mead simplex gradient-based optimisation procedure. The outcome of the optimisation study is a new blade design that is currently being tested in full-scale concept trials by a partnering wind energy company.