Contrasting the Parasitic Torque on a Drag-Driven VAWT through a Variable-Blade Rotor Architecture

Abstract:

The present work exhibits a further development of a mean for furthering conventional drag-driven VAWT technology by contrasting the counter-rotating (parasitic) torque generated from drag-driven vertical-axis wind turbine (VAWT) blades travelling into the wind through the use of a variable rotor blade geometry. A former research on water tank experimental tests on a small rotor characterized by three horizontal blades having variable geometry has been presented [. Each blade was obtained by connecting a horizontal flat plate to a tilting one swinging over a horizontal axis, so that the tilt angle between the two plates could vary depending on flow field conditions. In this paper several open-field measurements at different free-stream wind velocities have been carried out, in order to characterize the energy performance of the rotor for two different blade profile architectures: first experimental investigations were performed on a fixed-angle blade configuration of 41.3 degs between the horizontal and the inclined flat plates. Then, attention mainly focused on tilting blades, achieving a quantification of the influence of blade swinging on overall rotor performance. A full campaign of analysis was completed for both blade configurations and overall rotor torque and power were analyzed as a function of incoming wind velocity and rotor angular speed, resulting the variable-blade configuration maximum power coefficients much higher with respect to the corresponding classical drag-type fixed-blade architecture.

• Periodical: Applied Mechanics and Materials (Volumes 325-326)
• Pages: 260-264
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.325-326.260
• Online since: June 2013
• Authors: Marco Raciti Castelli, Ernesto Benini
• Keywords: Drag-Driven, Open-Field Testing, Parasitic Torque, VAWT

References

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