An extension of the Blade Element Momentum method applied to Diffuser Augmented Wind Turbines

This work presents an innovative approach to the analysis of Diffuser Augmented Wind Turbines (DAWTs) using the Blade Element Momentum (BEM) Method, Computational Fluid Dynamics (CFD) calculation on diffusers and conservation principles. In this model the geometry of the rotor is considered as a one-dimensional analysis, in which a hypothesis is made to extend the Glauert’s correction to avoid the high values of the axial induction factor. For the coupling with the diffuser, CFD calculation is performed on an axisymmetric hypothesis. The results for the estimated diffuser velocity speed-up ratio agree with the experimental data. The same behavior is obtained for the torque and the output power when compared to the numerical and experimental results available from the literature.