Investigation of Counter-Rotating Wind Turbine Performance using Computational Fluid Dynamics Simulation

Investigation of the dual rotor counter-rotating wind turbine (CRWT) performance using non-dimensional parameters of the rotor diameter ratio and the rotor axial distance ratio against the characteristics of power coefficient with tip speed ratio (TSR) as input parameters have been successfully carried through CFD simulation. CFD simulation used k-e turbulence realizable with hexahedral meshing to predict the CRWT performance to the rotor diameter ratio of D-1/D-2<1, D-1/D-2 = 1 and D-1/D-2>1 and rotor axial distance ratio with the s826 airfoil that has been applied to the single rotor wind turbine. The best CRWT performance obtained on the rotor diameter ratio of D-1/D-2 = 1.0 with the peak power coefficient of 0.5219 or increased to Delta C-P, (max) = 16.49% from the single rotor. CRWT performance through the addition of rotor axial distance ratio showed the power coefficient of the front rotor continued to rise closely to the single rotor performance while the rear rotor will continue to decline. However, the overall CRWT performance were relatively stable after the ratio of the distance Z/D-1 = 0.5 with the peak power coefficient of 0.5348 or increased to Delta C-P, (max) = 19.37%.