Design and Test Campaign of a Ducted Horizontal Axis Wind Turbine
Electrical energy production by wind energy has assumed more and more relevance in the last years. This paper presents the design of a ducted horizontal axis wind turbine, in order to enhance the performance. The study compares the energy production 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 a quasi-1D model, using correlations from literature to evaluate pressure, velocity and producible electrical power by the wind turbine. A 3D CFD model, in a set of configurations, has confirmed the preliminary results. The most promising geometries have been selected by combining the outputs of the two models. In order to confirm the results obtained by the numerical models, a test rig has been assembled at the wind tunnel of the Polytechnic School of the University of Genoa. Different possible configurations of the wind energy harvesting system have been tested: free turbine, horizontal duct, convergent duct and convergent-divergent ducts (with the turbine installed in the throat section). In particular, the convergent-divergent duct has shown the best results, with an increase factor close to 2.5 in terms of produced power, compared to the reference free turbine. Finally, the results obtained in the experimental campaign have been used to validate the two models (1D and 3D CFD). Considering the advantages in terms of energy production, this kind of configuration can be considered an interesting solution for many different situations, including energy harvesting.