Efficiency improvement of a new vertical axis wind turbine by individual active control of blade motion

Effect of number of blades on aerodynamic forces on a straight-bladed Vertical Axis Wind Turbine

“…In order to carry out quantitative analysis, the pressure coefficient C p is defined by Refs. [17,28]:…”

“…et al [17] presented a commercial CFD program analysis of energy performance and aerodynamic force on a four-bladed VAWT at different pitch angles. From this work, it can be seen that changing the pitch angle has a pronounced effect on power coefficient.…”

Numerical Investigations of a Vertical Axis Wind Turbine with Variable Pitch

“…The numerical time step is based on the characteristic time flow ( 2 / / 360 t s     ); after three revolutions the solution became periodical. Figure 5 shown the velocity field in the rotor zone at azimuthal angles between 0 0 and 180 0 , for angular velocity of  = 15 rad/s (2.4 rev/s), corresponding to tip speed ratio of 0.5, in the left side VAWT with fixed pitch; and in the right side-VAWT with variable pitch [6][7][8][9]. Figure 6 shown the aerodynamic moment relative to the axis of rotation.…”

Study on Synchronous Variable-Pitch Vertical Axis Wind Turbine

“…However, the shortcoming that they are not easy to self-start has restricted their development [1]. To solve this problem, an effective method of controlling the pitch angles of blades so as to maximize the driving torque on the turbine has been developed [2][3][4]. But because traditional Darrieus turbines operate in the range of high tip speed ratios (λ), little attention has been paid to the study of optimum pitch-angle control laws in the range of low tip speed ratios (λ<1).…”