Evaluation of layout and atmospheric stability effects in wind farms using large‐eddy simulation
TLDR
In this article, the effect of wind farm configuration and atmospheric stability on the power generated by large wind farms was investigated using large-eddy simulation (LES) and three stabilities (neutral and moderately unstable and stable).Abstract:
Large-eddy simulation (LES) has been used previously to study the effect of either configuration or atmospheric stability on the power generated by large wind farms. This is the first study to consider both stability and wind farm configuration simultaneously and methodically with LES. Two prevailing wind directions, two layouts (turbines aligned versus staggered with respect to the wind) and three stabilities (neutral and moderately unstable and stable) were evaluated. Compared with neutral conditions, unstable conditions led to reduced wake losses in one configuration, to enhanced wake losses in two and to unchanged wake losses in one configuration. Conversely, stable conditions led to increased wake losses in one, decreased wake losses in two and unchanged wake losses in one configuration. Three competing effects, namely, rates of wake recovery due to vertical mixing, horizontal spread of wakes and localized regions of acceleration caused by multiple upstream wakes, were identified as being responsible for the observed trends in wake losses. The detailed flow features responsible for these non-linear interactions could only be resolved by the LES. Existing analytical models ignore stability and non-linear configuration effects, which therefore need to be incorporated. Copyright © 2017 John Wiley & Sons, Ltd.read more
Citations
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Atmospheric Stability Affects Wind Turbine Power Collection
Sonia Wharton,Julie K. Lundquist +1 more
TL;DR: In this paper, the authors examined turbine power generation data, segregated by atmospheric stability, in order to investigate power performance dependences at a West Coast North American wind farm and found that the power generated at a given wind speed is higher under stable conditions and lower under strongly convective conditions.
Journal ArticleDOI
Review and evaluation of wake loss models for wind energy applications
Cristina L. Archer,Ahmadreza Vasel-Be-Hagh,Ahmadreza Vasel-Be-Hagh,Chi Yan,Sicheng Wu,Yang Pan,Joseph F. Brodie,Joseph F. Brodie,A. Eoghan Maguire +8 more
TL;DR: In this article, the authors examined the performance of six well-known analytical wake loss models, namely, Jensen, Larsen, Frandsen, Bastankah and Porte-Agel (BPA), Xie and Archer (XA), and Geometric Model (GM), by comparing their absolute error, bias, correlation coefficient, and ability to predict power production within one standard deviation of the mean observed values at three major commercial wind farms.
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Wind farm hub height optimization
TL;DR: In this article, the effect of hub height optimization on the annual energy production (AEP) of a wind farm is assessed. But the only optimization variable is the hub height of each wind turbine and all other characteristics of the wind farm, including base location, rotor diameter and total number of wind turbines, remain unchanged.
Influence of atmospheric stability on wind-turbine wakes: A large-eddy simulation study
Mahdi Abkar,Fernando Porté-Agel +1 more
TL;DR: In this article, large-eddy simulation is combined with a turbine model to investigate the influence of atmospheric thermal stability on wind-turbine wakes, and the simulation results show that atmospheric stability has a significant effect on the spatial distribution of the mean velocity deficit and turbulence statistics in the wake region as well as the wake meandering characteristics downwind of the turbine.
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Flow Adjustment Inside and Around Large Finite-Size Wind Farms
Ka Ling Wu,Fernando Porté-Agel +1 more
TL;DR: In this article, large-eddy simulations are performed to investigate the flow inside and around large finite-size wind farms in conventionally-neutral atmospheric boundary layers, including the induction, entrance and development, fully-developed, exit and farm wake regions.
References
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Book
An Introduction to Boundary Layer Meteorology
TL;DR: In this article, the boundary layer is defined as the boundary of a boundary layer, and the spectral gap is used to measure the spectral properties of the boundary layers of a turbulent flow.
Journal ArticleDOI
Flux-Profile Relationships in the Atmospheric Surface Layer
TL;DR: In this article, the free constants in several interpolation formulas can be adjusted to give excellent fits to the wind and temperature gradient data, and the behavior of the gradients under neutral conditions is unusual, however, and indicates that von Karman's constant is ∼0.35, rather than 0.40 as usually assumed, and that the ratio of eddy diffusivities for heat and momentum at neutrality is ∼1.0.
Journal ArticleDOI
A Lagrangian dynamic subgrid-scale model of turbulence
TL;DR: In this paper, the Smagorinsky eddy-viscosity model is combined with a spatially averaged dynamic model for complex-geometry inhomogeneous flows, and a new dynamic model formulation is introduced that combines advantages of the statistical and local approaches.
Journal ArticleDOI
Large eddy simulation study of fully developed wind-turbine array boundary layers
TL;DR: In this paper, a suite of large eddy simulations (LES), in which wind turbines are modeled using the classical "drag disk" concept, is performed for various wind-turbine arrangements, turbine loading factors, and surface roughness values.