CFD study on wake characteristics of a dual rotor wind turbine using different turbulence models

Abstract The computational fluid dynamics (CFD) method is widely used in wind turbine wake characteristics simulation. The dual-rotor wind turbine has attracted the attention of researchers because of the wind energy utilization rate that is difficult to surpass by the traditional single-rotor wind turbine. Using the CFD method to study the wake of the fan needs to complete the steps of modeling, meshing, simulation, and post-processing. Reynolds average Navier-Stokes (RANS) model and large eddy simulation (LES) model are two commonly used turbulence models in CFD calculation. The flow field can be simulated efficiently and accurately by using the considerate hybrid grid. This paper uses a full-scale wind turbine model, body-fitted hybrid grid, RANS, and LES turbulence models to conduct CFD numerical simulation on a dual-rotor wind turbine to analyze its wake characteristics. It was found that the LES model shows obvious advantages in instantaneous wind speed and vorticity, and the richness of its details is more helpful for researchers in analyzing the results accurately. The dual-rotor wind turbine shows the fusion of two wind turbine wakes in the far wake region, resulting in the expansion of the wake region and the irregularity of the far wake region.