Abstract
| Original language | English |
|---|---|
| Journal | Journal of Fluid Mechanics |
| Volume | 846 |
| Pages (from-to) | 190-209 |
| Number of pages | 20 |
| ISSN | 0022-1120 |
| DOIs | |
| Publication status | Published - 2018 |
Bibliographical note
This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.Keywords
- Nonlinear instability
- Vortex shedding
- Wakes
Cite this
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Far-wake meandering induced by atmospheric eddies in flow past a wind turbine. / Mao, Xiaojian; Sorensen, J. N.
In: Journal of Fluid Mechanics, Vol. 846, 2018, p. 190-209.Research output: Contribution to journal › Journal article › Research › peer-review
TY - JOUR
T1 - Far-wake meandering induced by atmospheric eddies in flow past a wind turbine
AU - Mao, Xiaojian
AU - Sorensen, J. N.
N1 - This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
PY - 2018
Y1 - 2018
N2 - A novel algorithm is developed to calculate the nonlinear optimal boundary perturbations in three-dimensional incompressible flow. An optimal step length in the optimization loop is calculated without any additional calls to the Navier-Stokes equations. The algorithm is applied to compute the optimal inflow eddies for the flow around a wind turbine to clarify the mechanisms behind wake meandering, a phenomenon usually observed in wind farms. The turbine is modelled as an actuator disc using an immersed boundary method with the loading prescribed as a body force. At Reynolds number (based on free-stream velocity and turbine radius) Re = 1000, the most energetic inflow perturbation has a frequency omega = 0.8-2, and is in the form of an azimuthal wave with wavenumber m = 1 and the same radius as the actuator disc. The inflow perturbation is amplified by the strong shear downstream of the edge of the disc and then tilts the rolling-up vortex rings to induce wake meandering. This mechanism is verified by studying randomly perturbed flow at Re
AB - A novel algorithm is developed to calculate the nonlinear optimal boundary perturbations in three-dimensional incompressible flow. An optimal step length in the optimization loop is calculated without any additional calls to the Navier-Stokes equations. The algorithm is applied to compute the optimal inflow eddies for the flow around a wind turbine to clarify the mechanisms behind wake meandering, a phenomenon usually observed in wind farms. The turbine is modelled as an actuator disc using an immersed boundary method with the loading prescribed as a body force. At Reynolds number (based on free-stream velocity and turbine radius) Re = 1000, the most energetic inflow perturbation has a frequency omega = 0.8-2, and is in the form of an azimuthal wave with wavenumber m = 1 and the same radius as the actuator disc. The inflow perturbation is amplified by the strong shear downstream of the edge of the disc and then tilts the rolling-up vortex rings to induce wake meandering. This mechanism is verified by studying randomly perturbed flow at Re
KW - Nonlinear instability
KW - Vortex shedding
KW - Wakes
U2 - 10.1017/jfm.2018.275
DO - 10.1017/jfm.2018.275
M3 - Journal article
VL - 846
SP - 190
EP - 209
JO - Journal of Fluid Mechanics
JF - Journal of Fluid Mechanics
SN - 0022-1120
ER -