Performance investigations of modified asymmetric blade H-Darrieus VAWT rotors

Wind is an important renewable energy resource, which can be extracted for power generation by horizontal and vertical axis wind turbines (VAWTs). VAWTs can be installed in low wind speed regimes for small-scale power generation. However, for better performance in such a scenario, an improved rotor blade configuration is essential. This paper investigates the performances of an asymmetric blade H-Darrieus rotor with a blade span constant relative thickness (RT) and a variable thickness (VT) at different low wind speeds between 4 and 6 m/s. Both static and steady-state performances have been evaluated. Different blade span thickness to chord ratios (t/c) of 30% and 45% (constant RT case) are considered by increasing the blade thickness of the considered base profile NACA 63-415 while keeping the chord length same (5.0 cm). After determining the optimal blade RT, a new blade span variable thickness (VT) H-Darrieus rotor has been designed with a thicker portion (t/c =37.5%) on the top end and a thinner porti...