Performance improvement of Savonius wind turbine with porous deflectors: A CFD approach

Authors: Md Mahmud Hasan Saikot, Mahfuzur Rahman, Md. Anwar Hosen, Wasif Ajwad, Md. Faiyaz Jamil, and Md Quamrul Islam

Abstract

In the present study, two porous deflectors are placed upstream of a Savonius wind turbine to augment its performance using Computational Fluid Dynamics (CFD). One of the porous deflectors is placed in front of the returning blade following a previously studied configuration. Several parameters of the other deflector, placed near the advancing blade, such as porosity, angle, position, and length, are varied to maximize the turbine efficiency numerically. The SST k- 𝜔 turbulence model was used to solve the two-dimensional (2D) flow field using incompressible unsteady Navier-Stokes equations. The optimized case exhibits a 26% improvement in power coefficient compared to the single porous deflector at a tip speed ratio of 0.9. Domain dimensions have also been investigated to mitigate the overestimation of the performance coefficient resulting from the blockage effect. The self-starting capability of the turbine shows a significant improvement as well.

Original research article submitted to TCFD (Springer)