Numerical Investigation of Effects of Turbulence Intensity on Aerodynamic Performance for Straight-Bladed Vertical-Axis Wind Turbines

Abstract

Vertical-axis wind turbines (VAWTs) may be subjected to varying degrees of turbulence in practice. In the present study, the computational fluid dynamics (CFD) method and improved delayed detached eddy simulation (IDDES) turbulence model are adopted to investigate the effects of turbulence intensity on the aerodynamic performance of single and dual straight-bladed VAWTs. The reliability of the numerical model is verified by available experiments. Then, the power performance, wake characteristics, and turbulence statistics distribution of a single VAWT under different inlet conditions are analyzed. Besides, the aerodynamic interaction between two arrayed VAWTs in the turbulent flow are explored. The results show that higher turbulence intensities could significantly improve the power coefficients of the VAWT under low and medium inflow velocities. The aerodynamic loads on the blade are enlarged by the turbulent flow, and more fluctuations occur around the rotor. The strong ambient turbulence could provide constant momentum supplement for the turbine wake and accelerate the wake recovery. Moreover, the atmospheric turbulence has a positive effect on the total power output of dual VAWTs in a tandem arrangement.