The surface area requirements of an efficient diffuser has been reduced by innovative use of the external wind to produce a cost-effective wind energy conversion system (WECS). Three sets of tests were conducted on very compact diffusers: 1) on small-scale models using screens to simulate a real turbine; 2) on ten times larger scale models with screens; and 3) on a real turbine. The first-generation nonoptimized diffuser-augmented wind turbine (DAWT) configuration is a conical, 60 deg included angle diffuser with an area ratio of 2.78 controlled by two tangential injection slots for boundary-layer control. This baseline model provided over three times the power of a conventional WECS with the same turbine efficiency, diameter, and free wind. An optimized configuration should provide augmentations greater than four.

Experimental Demonstration of the Diff user-Augmented Wind Turbine Concept

Effect of shroud on the performance of horizontal axis hydrokinetic turbines

Experimental demonstration of the diffuser-augmented wind turbine concept

Diffuser augmented wind turbines: Review and assessment of theoretical models

. A synergistic design strategy for ducted horizontal axis wind
turbines (DWTs), utilizing the numerical solution of a ducted actuator disk
system as the input condition for a modified blade element momentum method,
is presented. Computational results of the ducted disk have shown that the
incoming flow field for a DWT differs substantially from that of a
conventional open rotor. The rotor plane velocity is increased in the ducted
flow field, and, more importantly, the axial velocity component varies
radially. An experimental full-scale 2.5 m rotor and duct were designed,
using this numerical strategy, and tested at the University of Waterloo's
wind turbine test facility. Experimental results indicated a very good
correlation of the data with the numerical predictions, namely a doubling of
the power output at a given velocity, suggesting that the numerical strategy can
provide a means for a scalable design methodology.

/pdf/experimental-validation-of-a-ducted-wind-turbine-design-1z7gwgt814.pdf

A. L. Loeffler

Papers

Inviscid flow through wide-angle diffuser with actuator disk