Clean Technology 2009
J.P. Abraha, G. Mowry, R. Erickson
University of St. Thomas, US
small-scale wind turbine, urban, rooftop
A novel, vertical-axis wind turbine has been designed and analyzed for use in crowded urban and rooftop environments. The features of the turbine include a contoured blade which maximizes the rotational velocity while minimizing drag. The analysis of the device consisted of a two-step procedure which encompassed a fully three-dimensional simulation of the fluid flow around the blade and then a time-stepping procedure that allowed the determination of the rotational velocity of the turbine. The calculations were carried out for wind velocities that ranged from 10 to 30 miles per hour. The resulting rotational velocity of the turbine was 137 revolutions per minute for wind velocities of 30 miles per hour. On the other hand, wind speeds of 20 and 10 miles per hour led to rotational velocities of 91 and 43 revolutions per minute, respectively. When the entire set of results was assembled, it was possible to provide a simple expression which relates the rotational velocity to wind speed. This result will enable wind-power developers to predict the rotation and subsequent power generation from the turbine in advance of installation. The results indicate that this turbine design will generate appreciable electricity for local consumption.