Experimental and numerical investigation of the effect of blade number on the aerodynamic performance of a small-scale horizontal axis wind turbine

Abstract

This study presents experimental and numerical investigation for the effect of number of blade (solidity) on the power and thrust coefficients of a small-scale horizontal-axis wind turbine HAWT. An experimental set- up was installed on wind turbine rotors with different number of blades, i.e. three, five and six, and at different tip speed ratios, in the closed-circuit open-test section wind tunnel. The obtained results from CFD simulations were performed to compare numerical data with experimental measurements. In addition, there is a lack of information presented for the effect of rotor blade number on the flow field for HAWT like vertical axis wind turbine VAWT. Therefore, the current study extends to study the effect of solidity on the flow field using numerical calculation. The numerical simulation was performed using a steady-RANS method. The SST k-ω turbulence model was used to represent turbulence characteristics. It is found that decreasing the number of blades (which makes the turbine less sensitive to the change in tip speed ratio) the wind turbine with 3 blade configuration has the maximum power coefficient in respect to 5 and 6 blade turbines, higher by around 2 and 4 percent respectively.