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ARTICLE

The Effects of Turbulence Intensity and Tip Speed Ratio on the Coherent Structure of Horizontal-Axis Wind Turbine Wake: A Wind Tunnel Experiment

Yuxia Han^1,2, Jianwen Wang^1,2,*, Xin Li³, Xueqing Dong^1,2, Caifeng Wen^1,2

1 School of Energy and Power Engineering, Inner Mongolia University of Technology, Hohhot, 010051, China
2 Key Laboratory of Wind Energy and Solar Energy Utilization Technology, Ministry of Education, Inner Mongolia University of Technology, Hohhot, 010051, China
3 Power Research Institute, Inner Mongolia Electric Power Group Co., Ltd., Hohhot, 010020, China

* Corresponding Author: Jianwen Wang. Email:

(This article belongs to this Special Issue: Wind Energy Development and Utilization)

Energy Engineering 2022, 119(6), 2297-2317. https://doi.org/10.32604/ee.2022.020858

Received 16 December 2021; Accepted 08 March 2022; Issue published 14 September 2022

Abstract

The evolution laws of the large-eddy coherent structure of the wind turbine wake have been evaluated via wind tunnel experiments under uniform and turbulent inflow conditions. The spatial correlation coefficients, the turbulence integral scales and power spectrum are obtained at different tip speed ratios (TSRs) based on the time-resolved particle image velocity (TR-PIV) technique. The results indicate that the large-eddy coherent structures are more likely to dissipate with an increase in turbulence intensity and TSR. Furthermore, the spatial correlation of the longitudinal pulsation velocity is greater than its axial counterpart, resulting into a wake turbulence dominated by the longitudinal pulsation. With an increase of turbulence intensity, the integral scale of the axial turbulence increases, meanwhile, its longitudinal counterpart decreases. Owing to an increase in TSR, the integral scale of axial turbulence decreases, whereas, that of the longitudinal turbulence increases. By analyzing the wake power spectrum, it is found that the turbulent pulsation kinetic energy of the wake structure is mainly concentrated in the low-frequency vortex region. The dissipation rate of turbulent kinetic energy increases with an increase of turbulence intensity and the turbulence is transported and dissipated on a smaller scale vortex, thus promoting the recovery of wake.

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Keywords

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