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The effects associated with the tilted blade tip section on power production and bending load are presented in this study. The blade tip's section of 0.045R size was inclined to the pressure and suction sides for cant angles within a range of -45° to +45°. National Renewable Energy Laboratory (NREL) 5MW wind turbine blade was used as a reference blade. The numerical computations were performed using the finite volume method through ANSYS Fluent version 19.1. First, the aerodynamic performance of different configurations was examined based on computation results of axial force, aerodynamic torque and bending load on flap-wise direction. The best performing blade configuration was selected for further investigations on pitch angle sensitivity for varying wind speed between rated wind speed and cut-out wind speed. A steady-state pressure based solver utilizing Semi-Implicit Method for Pressure Linked Equations (SIMPLE) algorithm was used to solve Reynolds Average Navier-Stoke (RANS) equations closed with k - ω Shear Stress Transport (SST) turbulence model. All blades with winglets increase aerodynamic torque. The winglets inclined to the suction side result in a higher increase of aerodynamic torque than the corresponding winglets tilted to the pressure side. The winglet tilted by a cant angle of 15° produced the highest aerodynamic torque increment by about 10% as compared to other blades with winglets. A similar performance trend was observed for the blade with and without winglet when the pitch angle was varied according to the specified wind speed. The general conclusion was made that a winglet can be used to enhance power extraction without the necessity to increase the rotor diameter. [ABSTRACT FROM AUTHOR]

The purpose of present study is to approve use of ANSYS software as a tool for wind turbine simulations. Based on workbench platform designmodeler, mechanical mesh and fluent components, the study attempts to reproduce experimental measurements performed on standstill outboard MEXICO blade section in the low speed low turbulence (LTT), a facility at Delft University of Technology. The outboard MEXICO blade section geometry same as the one used in experiments is adopted for numerical simulations. Three set of angle of attack are taken as variable with inlet velocity hold at 35 m/s and fluid flow viscosity at 1.462kgms-2 in every simulation. Steady state pressure based solver is utilized to solve continuity and momentum Navier-Stoke equations with k - ω SST turbulent model taken as closure. Pressure and velocity are decoupled via SIMPLE algorithm and discretization scheme specified to second order upwind for momentum, turbulent kinetic energy and dissipation rate, while pressure interpolation scheme settled to second order. Computed pressure coefficient around selected airfoil sections is compared to experiment measurements which include; RISOE_121 at 60%R and NACA64418 at 92%R. Comparison shows good agreement between the CFD simulation and experiment results, but slight variation is observed at around RISOE_121 airfoil. [ABSTRACT FROM AUTHOR]