Analysis and comparison of numerical methods for design and development of small Diffuser-Augmented Wind Turbine (DAWT)

The paper discusses results of examination of various wind turbine rotor models implemented in numerical simulations, with particular emphasis on the interaction of a rotor with the surrounding airflow. The study concerns a wind turbine placed at the inlet of a divergent duct, a solution known as Diffuser-Augmented Wind Turbine. 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 study focuses on the search of wind turbine evaluation method combining high accuracy and tolerable time-to-results factor. The examined models include: FRM (Fully-resolved Rotor Model), ADM (Actuator Disk Model) and authors' modified approach to ALM (Actuator Line Model). The study covers: the implementation of the above mentioned method(s) into a commercial solver ANSYS CFX 15.0, the comparison of the obtained results with available experimental data, the analysis of the results obtained from simulations and the discussion. The paper is characterised by the wide spectrum of actuator models compared with 3D accurate rotor modelling for the estimation of turbine performance, the authors' proposal of the ALM variant, and the comparison of the models also from the viewpoint of the numerical effort (computation time and resources necessary) they require.