Renewable Energy Resources and Technologies
Amir Hossein Zare; Esmail Mahmoodi; Mohsen Boojari; Ali Sarreshtehdari
Abstract
Significant growth of the wind power market has led to a dramatic increase in the scale and capacity of wind turbines over the past decades. As these extreme-scale structures are expected to pose a wide range of challenges, an innovative concept which both lightens blade's mass and improves their aerodynamic ...
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Significant growth of the wind power market has led to a dramatic increase in the scale and capacity of wind turbines over the past decades. As these extreme-scale structures are expected to pose a wide range of challenges, an innovative concept which both lightens blade's mass and improves their aerodynamic performance, is vital for the future of rotor's design. In the present study, modeling and evaluating of an innovative pre-aligned rotor design based on SANDIA SNL100-00 wind turbine blade were accomplished. To evaluate the aerodynamic performance of the proposed rotor, CFD simulation was used as a well-developed technique in fluid mechanic. In the new rotor design, the swept area was increased using an equal blade length and the blade sections were more appropriately aligned with the wind flow compared to the reference model. This enhancement attained due to transferring the bending position from the root to a certain point alongside the length of blade. According to simulation assessments, this modification led to the overall improvement of main performance parameters in terms of the mean power and the applied torque on the blades. The simulation revealed that the novel concept is capable of increasing the mean power coefficient by 13.21 % compared to the conventional rotor designs. Analysis of the axial induction in front of the rotor plane displayed a greater drop in the flow velocity streaming up to the rotor, which could lead to have a more efficient configuration for harnessing the upcoming wind's power.
Renewable Energy Resources and Technologies
Nemat Keramat Siavasha; Gholamhasan Najafi; Teymour Tavakoli; Barat Ghobadian; Esmail Mahmoodi
Abstract
Ducted wind turbines are a kind of small wind turbine having a diffuser or any other shape around the rotor which increases the air flow through the blades and absorbs more power. In the present study, a small wind turbine was ducted with a relatively simple ring and its performance was investigated ...
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Ducted wind turbines are a kind of small wind turbine having a diffuser or any other shape around the rotor which increases the air flow through the blades and absorbs more power. In the present study, a small wind turbine was ducted with a relatively simple ring and its performance was investigated in a wind tunnel. The duct is shaped using rolling steel sheets on a sloping surface and finally fabricated in double-glazed surfaces. The turbine utilizes polyester resin glass fiber-armed composite hollow blades. Bare turbine produces 165 watts in its highest power generation mode which can reach 282 watts when it is ducted. The evaluation of the system in the wind tunnel showed that the power generation of the ducted system compared to a conventional turbine was 14 % higher on average. Furthermore, the rotor speed of the ducted turbine was 45 % higher than the bare one which increases the tip speed ratio (TSR). In this study, TSR increment raised the absorbed power in the developed wind turbine.