Numerical investigation of the influence of shear and thermal stratification on the wind turbine tip-vortex stability
Author(s)
Hodgkin, Amy
Laizet, Sylvain
Deskos, Georgios
Type
Journal Article
Abstract
The interaction between wind turbine wakes and atmospheric turbulence is characterised
by complex dynamics. In this study, two major components of the atmospheric boundary
layer dynamics have been isolated, namely, the mean velocity profile shear and the thermal
stratification, to examine their impact on the near-wake development by undertaking a
series of highly resolved large-eddy simulations. Subsequently, instantaneous flow fields are
extracted from the simulations and used to conduct Fourier analysis and proper orthogonal
decomposition (POD) and compute the mean kinetic energy fluxes by different POD modes
to better understand the tip-vortex instability mechanisms. Our findings indicate that shear
can significantly affect the breakup of the wind turbine tip-vortices as well as the shape
and stable length of the wake, whereas thermal stratification seems to only have limited
contribution to the spatial development of the near-wake field. Finally, our analysis shows
that the applied perturbation frequency determines the tip-vortex breakup location as it
controls the onset of the mutual inductance instability.
by complex dynamics. In this study, two major components of the atmospheric boundary
layer dynamics have been isolated, namely, the mean velocity profile shear and the thermal
stratification, to examine their impact on the near-wake development by undertaking a
series of highly resolved large-eddy simulations. Subsequently, instantaneous flow fields are
extracted from the simulations and used to conduct Fourier analysis and proper orthogonal
decomposition (POD) and compute the mean kinetic energy fluxes by different POD modes
to better understand the tip-vortex instability mechanisms. Our findings indicate that shear
can significantly affect the breakup of the wind turbine tip-vortices as well as the shape
and stable length of the wake, whereas thermal stratification seems to only have limited
contribution to the spatial development of the near-wake field. Finally, our analysis shows
that the applied perturbation frequency determines the tip-vortex breakup location as it
controls the onset of the mutual inductance instability.
Date Issued
2022-07
Date Acceptance
2022-03-22
Citation
Wind Energy, 2022, 25 (7), pp.1270-1289
ISSN
1095-4244
Publisher
Wiley Open Access
Start Page
1270
End Page
1289
Journal / Book Title
Wind Energy
Volume
25
Issue
7
Copyright Statement
© 2022 The Authors. Wind Energy published by John Wiley & Sons Ltd.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
License URL
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (EPSRC)
Identifier
https://onlinelibrary.wiley.com/doi/10.1002/we.2728
Grant Number
EP/R023926/1
EP/V000942/1
Subjects
Science & Technology
Technology
Energy & Fuels
Engineering, Mechanical
Engineering
near-wake field
shear
stable wake length
thermal stratification
tip-vortex stability
LARGE-EDDY SIMULATION
BOUNDARY-LAYER
TURBULENCE
VORTICES
MULTIPLE
SCHEMES
IMPACT
WAKES
0906 Electrical and Electronic Engineering
0913 Mechanical Engineering
0915 Interdisciplinary Engineering
Energy
Publication Status
Published
Date Publish Online
2022-04-17