Enhancing rotor performance of a small-scale drag-type vertical-axis wind turbine with vertical guide vanes through Taguchi optimization

This study used FlowVision, a commercial CFD software, to simulate the operation of a small-scale drag-type vertical-axis wind turbine with vertical guide vanes. The simulations were conducted ranging from 4 m/s to 8 m/s, which reflects typical conditions for small-scale wind turbines. The rotor blades and guide vanes were optimized using the Taguchi method to improve the rotor performance. In the Taguchi optimization, the control factors investigated were the blade diameter, number of blades, and number of guide vanes. How these factors affect the rotor’s performance was discussed. The results indicated that the number of guide vanes most significantly influenced the rotor rotation of the investigated control factors. The blades and the guide vanes exhibited significant interactions. The guide vanes functioned as flow augmenters, directing and accelerating incoming airflow into the rotor. They also shield incoming airflow to prevent it from affecting the returning blades. However, using an excessive number of guide vanes may result in low rotor speed. The optimum wind turbine configuration was 8 blades, blades with D/Dr = 0.25 in diameter, and 6 guide vanes. The maximum power coefficient CP,max for the optimum configuration was 55.56% higher than that for the worst configuration.