Numerical simulation of Lucid spherical turbine and investigation the effect of different parameters of blades on its performance

In this paper the research has been performed on the cross-axis flow Lucid spherical turbine. Three-dimensional steady numerical simulation is used to determine power output and performance of this kind of turbines for low velocities in a channel. The k-ω SST turbulence model is used to perform the turbulent steady flows around the turbine. Further, Bachant and Wosnik's experimental data reported for spherical Lucid turbine, is employed to confirm the simulations. The influence of three effective parameters of blades, including the chord length, the number of blades and the type of airfoil section on the turbine performance are investigated over a range of tip-speed-ratios. It was found that increasing the blade chord length in lower speed tip ratios cause to increase the power coefficient up to %15 compared to the original version. Also, for the turbine with three blades, the best results were obtained by which, the power coefficient increased by 12.5%. Finally, it is obtained that using asymmetric airfoil section for blades has a positive effect on the turbine performance.