Large-eddy simulation of a very large wind farm in a stable atmospheric boundary layer

2011 ◽  
Vol 23 (6) ◽  
pp. 065101 ◽  
Author(s):  
Hao Lu ◽  
Fernando Porté-Agel
Keyword(s):  
Boundary Layer ◽  
Large Eddy Simulation ◽  
Atmospheric Boundary Layer ◽  
Wind Farm ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Stable Atmospheric Boundary Layer ◽  
Large Wind

Turbulence and Vertical Fluxes in the Stable Atmospheric Boundary Layer. Part I: A Large-Eddy Simulation Study

2013 ◽  
Vol 70 (6) ◽  
pp. 1513-1527 ◽  
Author(s):  
Jing Huang ◽  
Elie Bou-Zeid
Keyword(s):  
Boundary Layer ◽  
Large Eddy Simulation ◽  
Atmospheric Boundary Layer ◽  
Length Scale ◽  
Quasi Equilibrium ◽  
Turbulent Structures ◽  
Constant Length ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Stable Atmospheric Boundary Layer

Abstract This study seeks to quantitatively and qualitatively understand how stability affects transport in the continuously turbulent stably stratified atmospheric boundary layer, based on a suite of large-eddy simulations. The test cases are based on the one adopted by the Global Energy and Water Cycle Experiment (GEWEX) Atmospheric Boundary Layer Study (GABLS) project, but with a largely expanded stability range where the gradient Richardson number (Rig) reaches up to around 1. The analysis is mainly focused on understanding the modification of turbulent structures and dynamics with increasing stability in order to improve the modeling of the stable atmospheric boundary layer in weather and climate models, a topic addressed in Part II of this work. It is found that at quasi equilibrium, an increase in stability results in stronger vertical gradients of the mean temperature, a lowered low-level jet, a decrease in vertical momentum transport, an increase in vertical buoyancy flux, and a shallower boundary layer. Analysis of coherent turbulent structures using two-point autocorrelation reveals that the autocorrelation of the streamwise velocity is horizontally anisotropic while the autocorrelation of the vertical velocity is relatively isotropic in the horizontal plane and its integral length scale decreases as stability increases. The effects of stability on the overall turbulent kinetic energy (TKE) and its budget terms are also investigated, and it is shown that the authors' large-eddy simulation results are in good agreement with previous experimental findings across varied stabilities. Finally, Nieuwstadt's local-scaling theory is reexamined and it is concluded that the height z is not a relevant scaling parameter and should be replaced by a constant length scale away from the surface, indicating that the z-less range starts lower than previously assumed.

Large-Eddy Simulation of Offshore Wind Farms for Power Prediction

2018 ◽  
Author(s):  
Micah Sandusky ◽  
Rey DeLeon ◽  
Inanc Senocak
Keyword(s):  
Boundary Layer ◽  
Large Eddy Simulation ◽  
Atmospheric Boundary Layer ◽  
Wind Field ◽  
Wind Farm ◽  
Power Production ◽  
Offshore Wind ◽  
Detailed Knowledge ◽  
Eddy Simulation ◽  
Large Eddy

Offshore wind turbines are mega structures that span a critical section of the lowest part of atmospheric boundary layer while experiencing significant wind shear. A detailed knowledge of the wind field through a wind farm as part of the atmospheric boundary layer is essential to design efficient farm layouts and estimate power production for grid integration. To address these needs, we present a micro-scale wind prediction model based on a large-eddy simulation paradigm. We consider actuator disk models with and without rotation to simulate the influence of turbines on the wind field and apply our computational capability to the well-known Horns Rev offshore wind farm in Denmark to estimate power production. Instead of using manufacturers power curve to estimate power production, we propose an alternative approach based on the control volume analysis of kinetic energy conservation around turbines.

scholarly journals Large-eddy simulation of turbulent flows over an urban building array with the ABLE-LBM and comparison with 3D MRI observed data sets

2020 ◽  
Author(s):  
Yansen Wang ◽  
Michael J. Benson
Keyword(s):  
Boundary Layer ◽  
Kinetic Energy ◽  
Large Eddy Simulation ◽  
Atmospheric Boundary Layer ◽  
Validation Study ◽  
Tall Building ◽  
Turbulent Wind ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Building Array

Abstract In this article we describe the details of an ABLE-LBM (Atmospheric Boundary Layer Environment-Lattice Boltzmann Model) validation study for urban building array turbulent flow simulations. The ABLE-LBM large-eddy simulation results were compared with a set of 3D magnetic resonance image (MRI) velocimetry data. The ABLE-LBM simulations used the same building layout and Reynolds numbers operated in the laboratory water channel. The building set-up was an evenly spaced orthogonal array of cubic buildings (height = H) with a central tall building (height = 3H) in the second row. Two building orientations, angled with 0°and 45° wind directions, were simulated with ABLE-LBM. The model produced horizontal and vertical fields of time-averaged velocity fields and compared well with the experimental results. The model also produced urban canyon flows and vortices at front and lee sides and over building tops that were similar in strength and location to the laboratory studies. The turbulent kinetic energy associated with these two wind directions were also presented in this simulation study. It is shown that the building array arrangement, especially the tall building, has a great effect on turbulent wind fields. There is a Karman vortex street on the lee side of the tall building. High turbulent intensity areas are associated with the vortex shedding motions at building edges. In addition, the wind direction is a very important factor for turbulent wind and kinetic energy distribution. This validation study indicated that ABLE-LBM is a viable simulation model for turbulent atmospheric boundary layer flows in the urban building array. The computational speed of ABLE-LBM using the GPU has shown that real-time LES simulation is realizable for a computational domain with several millions grid points.

scholarly journals Large eddy simulation study of the humidity variation in the shadow of a large wind farm

Wind Energy ◽  
2020 ◽  
Vol 23 (2) ◽  
pp. 423-431
Author(s):  
John Stephen Haywood ◽  
Adrian Sescu ◽  
Kevin Allan Adkins
Keyword(s):  
Large Eddy Simulation ◽  
Simulation Study ◽  
Wind Farm ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Large Wind
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