Experimental validation of a ducted wind turbine design strategy

Benjamin Kanya,Kenneth D Visser

doi:10.5194/wes-3-919-2018

Abstract

Abstract. 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.

Highlights

Wind energy has long been acknowledged as having the potential to supplement and even displace the carbon-based fuel needs of our society
The ducted wind turbine (DWT) concept has been fraught with controversy over the years yet still shows promise in improving the USD kWh−1 issue
There are, issues with DWTs that need to be addressed before their full potential can be realized, the foremost being the tradeoff of increased energy production against the increased use of materials, which usually results in a higher unit cost

Summary

Introduction

Wind energy has long been acknowledged as having the potential to supplement and even displace the carbon-based fuel needs of our society. The wide adoption of small wind energy, namely that with a swept rotor area of less than 200 m2, has been hampered, by higher unit costs and lower efficiency than that of their large-scale counterparts. Studies on small turbines at Clarkson University have focused on improving their efficiency, at lower wind speeds, with a focus on the key metric of cost per unit energy produced, namely USD kWh−1. Visser: Experimental validation of a ducted wind turbine design strategy al.’s (1978) extensive testing in the 1970s proposed that this occurred because the duct reduces the pressure behind the turbine, relative to that behind a conventional wind turbine, causing more air to be drawn through They suggested that they could have a performance efficiency of Cp = 1.57, defined as

Methods

Results

Conclusion