Analysis and optimal design of wind boosters for Vertical Axis Wind Turbines at low wind speed

Vertical Axis Wind Turbines (VAWTs) are usually chosen for urban areas where local average wind speed is low. However, standalone VAWTs are unable to generate mechanical power satisfactorily for best practice. This study presents analysis and optimal design of airflow controlling equipment for a VAWT, which is called a wind booster. The wind booster is proposed to be implemented with a VAWT in order to not only harvest energy with low availability at low wind speed, but also enhance performance of the VAWT at high wind speed. Particularly, the wind booster comprises a number of guide vanes, which are mounted around a VAWT. The guide vanes direct wind to impact VAWT blades at effective angles while passages between each guide vane are arranged to accelerate wind. The guiding and throttling effects of the wind booster are able to increase angular speed of a VAWT, leading to an increase in mechanical power of the VAWT. Optimal solutions of number, shape, and leading angle of guide vanes are determined by maximizing the coefficient of power. The proposed methodology can be generalized to determine optimal wind boosters for other types and dimensions of turbines from this study.