Energies 2012, 5(12), 5229-5242; doi:10.3390/en5125229
Article

Behavior of the Blade Tip Vortices of a Wind Turbine Equipped with a Brimmed-Diffuser Shroud

1,* email, 1email, 2email, 2email and 2email
Received: 3 November 2012; in revised form: 30 November 2012 / Accepted: 10 December 2012 / Published: 13 December 2012
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract: To clarify the behavior of the blade tip vortices of a wind turbine equipped with a brimmed-diffuser shroud, called a “Wind-Lens turbine”, we conducted a three-dimensional numerical simulation using a large eddy simulation (LES). Since this unique wind turbine consists of not only rotating blades but also a diffuser shroud with a broad-ring brim at the exit periphery, the flow field around the turbine is highly complex and unsteady. Previously, our research group conducted numerical simulations using an actuator-disc approximation, in which the rotating blades were simply modeled as an external force on the fluid. Therefore, the detailed flow patterns around the rotating blades and the shroud, including the blade tip vortices, could not be simulated. Instead of an actuator-disc approximation, we used a moving boundary technique in the present CFD simulation to simulate the flow around a rotating blade in order to focus especially on blade tip vortices. The simulation results showed a pair of vortices consisting of a blade tip vortex and a counter-rotating vortex which was generated between the blade tip and the inner surface of the diffuser. Since these vortices interacted with each other, the blade tip vortex was weakened by the counter-rotating vortex. The results showed good agreement with past wind tunnel experiments.
Keywords: wind turbine; diffuser; brim; vortex; noise; numerical simulation
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MDPI and ACS Style

Takahashi, S.; Hata, Y.; Ohya, Y.; Karasudani, T.; Uchida, T. Behavior of the Blade Tip Vortices of a Wind Turbine Equipped with a Brimmed-Diffuser Shroud. Energies 2012, 5, 5229-5242.

AMA Style

Takahashi S, Hata Y, Ohya Y, Karasudani T, Uchida T. Behavior of the Blade Tip Vortices of a Wind Turbine Equipped with a Brimmed-Diffuser Shroud. Energies. 2012; 5(12):5229-5242.

Chicago/Turabian Style

Takahashi, Shuhei; Hata, Yuya; Ohya, Yuji; Karasudani, Takashi; Uchida, Takanori. 2012. "Behavior of the Blade Tip Vortices of a Wind Turbine Equipped with a Brimmed-Diffuser Shroud." Energies 5, no. 12: 5229-5242.

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