CFD analysis of Diffuser Augmented Wind Turbine model for wind tunnel investigation

The paper discusses results of integration of experimental campaign with CFD studies, where a small wind turbine placed inside a wind tunnel test section has been examined. Investigation included determination of model size influence on flow blockage effects. The CFD model helps to reduce time spent at the experimental stand and, therefore, costs pointing to the model with acceptable dimensions. CFD has been also used to anticipate the loads that may be exerted on the model thus helping to understand necessary measures in the upcoming aeromechanics study of the construction. The study concerns a wind turbine placed inside a diffuser channel, a solution known as Diffuser Augmented Wind Turbine (DAWT). This type of wind energy converter has recently been an object of numerous studies at the Institute of Turbomachinery of Lodz University of Technology. The examined model sizes included: D_5, D_10, D_20, D_30, D_80 and D_real, where the number states the per cent of test object's cross section area related to the cross-section area of the wind tunnel outlet nozzle supplying air to the test location. The numerical study has been based on a commercial solver ANSYS CFX 15.0, the comparison of the obtained results with available experimental data for D_5, D_30 and D_80 models has been made, leading to the analysis of the results obtained and the conclusions.