Design and test campaign of a ducted horizontal axis wind turbine

Electrical energy production by wind energy has assumedmore and more relevance in the last years. This paper presentsthe design of a ducted horizontal axis wind turbine, in order toenhance the performance. The study compares the energyproduction of a ducted turbine to a traditional free turbine,highlighting the different features. In the first part of the work,different possible geometries have been investigated through aquasi-1D model, using correlations from literature to evaluatepressure, velocity and producible electrical power by the windturbine. A 3D CFD model, in a set of configurations, hasconfirmed the preliminary results. The most promisinggeometries have been selected by combining the outputs of thetwo models. In order to confirm the results obtained by thenumerical models, a test rig has been assembled at the windtunnel of the Polytechnic School of the University of Genoa.Different possible configurations of the wind energyharvesting system have been tested: free turbine, horizontalduct, convergent duct and convergent-divergent ducts (withthe turbine installed in the throat section). In particular, theconvergent-divergent duct has shown the best results, with anincrease factor close to 2.5 in terms of produced power,compared to the reference free turbine. Finally, the resultsobtained in the experimental campaign have been used tovalidate the two models (1D and 3D CFD). Considering theadvantages in terms of energy production, this kind ofconfiguration can be considered an interesting solution formany different situations, including energy harvesting.