Modelling of wake dynamics and instabilities of a floating horizontal-axis wind turbine under surge motion

• Published in: Energy (Oxford) Vol. 239; p. 122110
• Main Authors: Chen, Guang, Liang, Xi-Feng, Li, Xiao-Bai
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 15-01-2022; Elsevier BV
• Subjects: Aerodynamics; Amplitudes; Detached eddy simulation; Fluid flow; Grid method; Horizontal Axis Wind Turbines; IDDES; Mathematical models; Motion stability; Offshore floating horizontal-axis wind turbine (OFHAWT); Overset grid; Reynolds number; Reynolds stress; Sensitivity analysis; Simulation; Stress distribution; Surge motion; Turbines; Wake dynamics and instabilities; Wind effects; Wind power; Wake dynamics and instabilities; Overset grid; IDDES; Surge motion; Offshore floating horizontal-axis wind turbine (OFHAWT)
• ISSN: 0360-5442; 1873-6785
• DOI: 10.1016/j.energy.2021.122110

The aerodynamic performance and wake dynamics of wind turbines are known to be affected by platform surge motion. This study utilized an improved delayed detached eddy simulation combined with the overset grid method to investigate the effect of surge motion amplitudes and periods (frequencies) on the aerodynamics and wake instabilities of wind turbines. The effect of the Reynolds number and azimuthal increment sensitivity analysis (time step) on the wind turbine loads and flow fields were investigated in detail. A comparison of the mean loads of the power coefficient and thrust coefficient between the numerical simulation and experiment with a consistent Reynolds number shows that the grid and simulation parameters used in this study can accurately capture the flow field and aerodynamic performance of the wind turbine. A detailed analysis of the flow fields, wake vortex structure, and mean Reynolds stress distribution was utilized to explore the effect of surge motion amplitudes and periods on the wind turbine performance, as well as the mechanism of the wake instability. Our results indicate that the surge motion can improve the efficiency of power generation and promote wake instabilities and vortex interactions. Meanwhile, surge motion amplitudes and frequencies have a positive effect on the wake recovery.
•IDDES is employed to model aerodynamics performance and wake dynamics of OFHAWT under surge motion.•The flow field near the blade and wake region is analyzed in detail.•Surge motion promotes the wake instabilities and vortex interaction.•Surge motion amplitudes and frequencies have a positive effect on the wake recovery process.