Numerical Study of Effect of Blade Twist Modifications on the Aerodynamic Performance of Wind Turbine

Wiroj Beabpimai,Tawit Chitsomboon

doi:10.14710/ijred.8.3.285-292

Abstract

This paper aims to investigate aerodynamic performance of a wind turbine blade with twist modifications using computational fluid dynamics (CFD). The phenomenon of 3D stall-delay effect in relation to blade twist is the key feature to be investigated in order to improve efficiency of a wind turbine. The NREL (National Renewable Energy Laboratory) Phase VI wind turbine rotor was used for validation and as the baseline rotor. The baseline blade geometry was modified by increasing/decreasing the twist angles in the inboard, mid-board and outboard regions of the blade in the form of a symmetrical curve with maximum twist angle of 3°. The steady incompressible Reynolds-averaged Navier-Stokes (RANS) equations with the k-ω Shear Stress Transport (SST) turbulence closure model were used for the calculations at wind speeds ranging from 5-20 m/s. The computational results for the baseline Phase VI rotor were validated against experimental data and a good agreement was found. The computational results for the modified blades were compared against those of the baseline blade. It was found that increase of annual energy production of up to 5.1% could be achieved by this modification technique. ©2019. CBIORE-IJRED. All rights reserved

Highlights

Renewable and sustainable energies are increasingly being researched to provide the world with clean and reliable energy sources
The validation of computational fluid dynamics (CFD) was performed by comparing the simulation results with the baseline blade (i.e., National Renewable Energy Laboratory (NREL) Phase VI) experimental data (Simms et al 2001; Hand et al 2001)
There is a slight overprediction of the rotor power at 11 m/s wind speed, and an underprediction of the rotor power for high wind speeds of 15-20 m/s where massive flow separations occur

Summary

Introduction

Renewable and sustainable energies are increasingly being researched to provide the world with clean and reliable energy sources. Some interesting papers on solar and nanofluid can be found in references (Ahmadi et al, 2018(1)-(3), and Ramezanizadeh et al, 2019). Wind energy is another option which has experienced rapid growth during recent decades in terms of technology and commercialization. Research and development on making wind turbines to be more efficient and competitive are crucial. The rotor blades are very important parts of a wind turbine since they convert kinetic energy of the wind into mechanical power. Designing of wind turbine rotor blade to yield a high efficiency is a very challenging task since it involves various complicated aerodynamic manipulations

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