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Energies 2014, 7(5), 3256-3281; doi:10.3390/en7053256

A Multi-Element Diffuser Augmented Wind Turbine

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Received: 4 April 2014; in revised form: 11 May 2014 / Accepted: 13 May 2014 / Published: 19 May 2014
(This article belongs to the Special Issue Wind Turbines 2014)
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Abstract: A new class of diffuser augmented wind turbines (DAWTs) is presented. The new diffuser concept exploits aero-dynamic principles for the creation of high-lift airfoil configurations known from the aircraft industry. Combining this with our objective of obtaining a compact power-efficient design has enabled creation of a family of DAWT designs with energy capture potentials which exceed the power efficiency based on the diffuser exit area by 50%. The paper presents the 1D momentum theory governing the DAWTs, and discusses upper limits for power extraction, similar to the Betz limit applicable for bare Horizontal-Axis Wind Turbines (HAWTs). Inviscid axisymmetric panel code calculations are then used to drive the diffuser design towards higher power coefficients. Axisymmetric actuator disk Navier-Stokes calculations reveal the types of stall that inhibit the functionality of the ideal inviscid optimum, leading the design towards the new class of DAWTs. DAWT performance has been differently measured over time, creating confusion. Proper comparison with performance of existing DAWT designs is therefore emphasized. This involves reference to established literature results, and recalculation of earlier DAWT designs in an attempt to project all results onto a common metric.
Keywords: wind turbine; diffuser; power augmentation; actuator disk CFD; panel methods wind turbine; diffuser; power augmentation; actuator disk CFD; panel methods
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.

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MDPI and ACS Style

Hjort, S.; Larsen, H. A Multi-Element Diffuser Augmented Wind Turbine. Energies 2014, 7, 3256-3281.

AMA Style

Hjort S, Larsen H. A Multi-Element Diffuser Augmented Wind Turbine. Energies. 2014; 7(5):3256-3281.

Chicago/Turabian Style

Hjort, Søren; Larsen, Helgi. 2014. "A Multi-Element Diffuser Augmented Wind Turbine." Energies 7, no. 5: 3256-3281.

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