A 2D numerical simulation of blade twist effect on the aerodynamic performance of an asymmetric blade vertical axis wind turbine in low wind speed

Abstract

For urban areas, small-scale vertical axis wind turbine (VAWT) is a promising energy harvester due to its compact structure. However, VAWT’s performance is inferior in low wind speed of urban environment. Selection of proper design and operational parameters can give a desirable power output under such condition. In this paper, effect of trailing edge blade twist on aerodynamic performance of an asymmetric blade H-Darrieus VAWT at a wind speed (6.0 m/s) is investigated using 2D numerical simulation. Important aerodynamic parameters considering blade twists have been analysed. Although blade twist has not increased power coefficient magnificently, the same is improved with blade twist of 1º. However, further increase of the latter reduces the turbine performance. A maximum power coefficient of 0.171 is obtained at tip speed ratio 2.4 for 1º blade twist configuration. Hence, the present study shows that blade twist should be very low for low wind speed application of H-Darrieus VAWT.