Current Research | Renewable Energy

Investigation on Darrieus Type Straight Blade Vertical Axis Wind Turbine with Flexible Blade

In this study, a three-dimensional VAWT with a spanwise passively deformable flexible blade has been modelled. The study mainly focuses on the analysis of blade structure characteristics associated with the bending and twist deflection. Two types of flexible blade material and two strut locations supporting H-type blades are being investigated. The unsteady external loads and energy efficiency of VAWT with such designed flexible blade are also being analysed. The simulation results show that the bending and twist deflection peak is positively correlated with the turbine tip speed ratio. For a flexible blade, an unevenly distributed structural stress along the blade with a high stress regime in the vicinity of strut location has also been observed. Due to the rotational motion of a VAWT, the centrifugal force acting on VAWT blade plays an important role on the blade structure characteristics. Reduction of the blade stiffness results in an increase of the blade stress. Changing the strut location from middle to tip will cause a large area under high stress. The results also indicate that the VAWT with a highly flexible blade is not an efficient energy extraction device when it is compared to a less flexible or a rigid blade.

The animation of fluid contours of the vertical axis turbine with flexible blade is as follows:

The animation of displacement of the vertical axis turbine with flexible blade is as follows:

Please refer to:

Wendi Liu and Qing Xiao. "Investigation on Darrieus Type Straight Blade Vertical Axis Wind Turbine with Flexible Blade." Ocean Engineering 110 (2015): pp 339-356.

or click here to download »

Wendi Liu and Qing Xiao. "Bend and Twist Effect for Large-Scale Vertical Axis Turbine." 11th European Wave and Tidal Energy Conference Series (EWTEC) (2015).