CFD Aerodynamic Modeling of Ducted Dual-Rotor Wind Turbine

Abstract

Due to growing needs for energy in our life, research in the wind energy field has increased significantly. There has been global concern towards the development of smart techniques and devices that could optimize the energy conversion and maximize the output power from the wind. Investigating such alternative solutions is required in order to meet the continuous increase in the power demand. The Dual Rotor Wind Turbine system (DRWT) offers higher energy extraction rates from the wind. In the present study, it is proposed to utilize the dual rotor configuration in a ducted system using wind lens in order to enable its application in regions of low wind speeds. The aerodynamic performance of ducted dual rotor wind turbine is investigated using CFD to solve the three-dimensional, turbulent, steady, incompressible flow equations, using the k-ε realizable and k-ω shear stress transport (SST) turbulence models. Several difficulties due to the complexity of the investigated geometry and meshing requirements have been encountered. Mesh independence study was conducted to ensure the accuracy and validate the results. Power curves were obtained, detailed investigation of the wind turbine performance in different configurations were highlighted in order to explore the benefit and effect of each configuration on the output power. The final results of the combined configuration of the dual rotor wind turbine (DRWT) with lens shows a considerable improvement of the performance of the wind turbine over wide range of wind speeds.