Turbulence kinetic energy ≈ Turbulence kinetic energy
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Flow Structure and Turbulence in Wind Farms Open
Similar to other renewable energy sources, wind energy is characterized by a low power density. Hence, for wind energy to make considerable contributions to the world's overall energy supply, large wind farms (on- and offshore) consisting …
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Some Recent Developments in Turbulence Closure Modeling Open
Turbulence closure models are central to a good deal of applied computational fluid dynamical analysis. Closure modeling endures as a productive area of research. This review covers recent developments in elliptic relaxation and elliptic b…
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Temperature measurement techniques for gas and liquid flows using thermographic phosphor tracer particles Open
Optical diagnostics for fluid temperature measurements continue to further our understanding of flows involving heat transfer and/or chemical reactions, which are intrinsic to key areas including energy production, the process industries, …
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CFD and wind-tunnel analysis of outdoor ventilation in a real compact heterogeneous urban area: Evaluation using “air delay” Open
Outdoor urban ventilation in a real complex urban area is investigated by introducing a new ventilation indicator – the “air delay”. Computational Fluid Dynamics (CFD) simulations are performed using the 3D steady Reynolds-Averaged Navier-…
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Energy transfer, pressure tensor, and heating of kinetic plasma Open
Kinetic plasma turbulence cascade spans multiple scales ranging from macroscopic fluid flow to sub-electron scales. Mechanisms that dissipate large scale energy, terminate the inertial range cascade, and convert kinetic energy into heat ar…
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Complex terrain experiments in the New European Wind Atlas Open
The New European Wind Atlas project will create a freely accessible wind atlas covering Europe and Turkey, develop the model chain to create the atlas and perform a series of experiments on flow in many different kinds of complex terrain t…
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Atmospheric Boundary Layer Classification With Doppler Lidar Open
We present a method using Doppler lidar data for identifying the main sources of turbulent mixing within the atmospheric boundary layer. The method identifies the presence of turbulence and then assigns a turbulent source by combining seve…
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The onset of sediment transport in vegetated channels predicted by turbulent kinetic energy Open
This laboratory study advances our understanding of sediment transport in vegetated regions, by describing the impact of stem density on the critical velocity, U crit , at which sediment motion is initiated. Sparse emergent vegetation was …
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A New Analytical Wake Model for Yawed Wind Turbines Open
A new analytical wake model for wind turbines, considering ambient turbulence intensity, thrust coefficient and yaw angle effects, is proposed from numerical and analytical studies. First, eight simulations by the Reynolds Stress Model are…
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Wake flow in a wind farm during a diurnal cycle Open
The atmospheric boundary layer (ABL) undergoes substantial changes in its structure and dynamics in the course of a day due to the transient nature of forcing factors such as the surface fluxes of heat and momentum. The non-stationary natu…
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Incompressible Rayleigh–Taylor Turbulence Open
Basic fluid equations are the main ingredient in the development of theories of Rayleigh–Taylor buoyancy-induced instability. Turbulence arises in the late stage of the instability evolution as a result of the proliferation of active scale…
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Two Corrections for Turbulent Kinetic Energy Generated by Wind Farms in the WRF Model Open
As wind farms grow in number and size worldwide, it is important that their potential impacts on the environment are studied and understood. The Fitch parameterization implemented in the Weather Research and Forecasting (WRF) Model since v…
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Wind Turbine Wake Characterization with Nacelle-Mounted Wind Lidars for Analytical Wake Model Validation Open
This study presents the setup, methodology and results from a measurement campaign dedicated to the characterization of full-scale wind turbine wakes under different inflow conditions. The measurements have been obtained from two pulsed sc…
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Nature of Kinetic Scale Turbulence in the Earth's Magnetosheath Open
We present a combined observational and theoretical analysis to investigate the nature of plasma turbulence at kinetic scales in the Earth’s magnetosheath. In the first decade of the kinetic range, just below the ion gyroscale, the turbule…
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Wind tunnel study of the wind turbine interaction with a boundary-layer flow: Upwind region, turbine performance, and wake region Open
Comprehensive wind tunnel experiments were carried out to study the interaction of a turbulent boundary layer with a wind turbine operating under different tip-speed ratios and yaw angles. Force and power measurements were performed to cha…
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Kinetic Turbulence in Relativistic Plasma: From Thermal Bath to Nonthermal Continuum Open
We present results from particle-in-cell simulations of driven turbulence in magnetized, collisionless, and relativistic pair plasmas. We find that the fluctuations are consistent with the classical k_{⊥}^{-5/3} magnetic energy spectrum at…
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CFD simulations of near-field pollutant dispersion with different plume buoyancies Open
This study performs computational fluid dynamics simulations for flow and dispersion fields around an isolated cubic building model with tracer gases being exhausted from an exit behind the building. The tracer gases have three different b…
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Assessing the Effects of Langmuir Turbulence on the Entrainment Buoyancy Flux in the Ocean Surface Boundary Layer Open
Large-eddy simulations (LESs) with various constant wind, wave, and surface destabilizing surface buoyancy flux forcing are conducted, with a focus on assessing the impact of Langmuir turbulence on the entrainment buoyancy flux at the base…
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Wind turbine power production and annual energy production depend on atmospheric stability and turbulence Open
Using detailed upwind and nacelle-based measurements from a General Electric (GE) 1.5sle model with a 77 m rotor diameter, we calculate power curves and annual energy production (AEP) and explore their sensitivity to different atmospheric …
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Broadening of Cloud Droplet Spectra through Eddy Hopping: Turbulent Adiabatic Parcel Simulations Open
This paper investigates spectral broadening of droplet size distributions through a mechanism referred to as the eddy hopping. The key idea, suggested a quarter century ago, is that droplets arriving at a given location within a turbulent …
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A Turbulence‐Based Bed‐Load Transport Model for Bare and Vegetated Channels Open
Previous studies have shown that sediment transport models based on bed shear stress ( τ ) are not accurate for regions with vegetation. The present study demonstrated that the inaccuracy arises from the influence of vegetation‐generated t…
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Cavitation characteristics around a sphere: An LES investigation Open
Here we examine partial and supercavitation over a sphere at a constant Reynolds number of 1.5 × 106 and a broad range of cavitation numbers (0.36 <σ< 1). Large eddy simulation (LES) and Sauer mass transfer model were used to simulate the …
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Modelling cluster wakes and wind farm blockage Open
We present two new models for wind turbine interaction effects and a recipe for combining them. The first model is an extension of the Park model, which explicitly incorporates turbulence, both the ambient atmospheric turbulence and the tu…
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Measurements of wind turbulence parameters by a conically scanning coherent Doppler lidar in the atmospheric boundary layer Open
The method and results of lidar studies of spatiotemporal variability of wind turbulence in the atmospheric boundary layer are reported. The measurements were conducted by a Stream Line pulsed coherent Doppler lidar (PCDL) with the use of …
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An Extended Eddy‐Diffusivity Mass‐Flux Scheme for Unified Representation of Subgrid‐Scale Turbulence and Convection Open
Large‐scale weather forecasting and climate models are beginning to reach horizontal resolutions of kilometers, at which common assumptions made in existing parameterization schemes of subgrid‐scale turbulence and convection—such as that t…
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U.S. East Coast Lidar Measurements Show Offshore Wind Turbines Will Encounter Very Low Atmospheric Turbulence Open
The rapid growth of offshore wind energy requires accurate modeling of the wind resource, which can be depleted by wind farm wakes. Turbulence dissipation rate ( ϵ ) governs the accuracy of model predictions of hub‐height wind speed and th…
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A Three-Dimensional Scale-Adaptive Turbulent Kinetic Energy Scheme in the WRF-ARW Model Open
A new three-dimensional (3D) turbulent kinetic energy (TKE) subgrid mixing scheme is developed using the Advanced Research version of the Weather Research and Forecasting (WRF) Model (WRF-ARW) to address the gray-zone problem in the parame…
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Turbulent kinetic energy estimates from profiling wind LiDAR measurements and their potential for wind energy applications Open
This study shows that turbulent kinetic energy (TKE) estimates, derived from static LiDARs in Doppler Beam Swing (DBS) mode, permit a qualitative and quantitative characterization and analysis of turbulent structures as wind turbine wakes,…
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Surface correlations of hydrodynamic drag for transitionally rough engineering surfaces Open
Rough surfaces are usually characterised by a single equivalent sand-grain roughness height scale that typically needs to be determined from laboratory experiments. Recently, this method has been complemented by a direct numerical simulati…
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Wind tunnel measurement of three-dimensional turbulent flow structures around a building group: Impact of high-rise buildings on pedestrian wind environment Open
The wind velocity and surface pressure of the model of a group of urban blocks made of low-rise buildings with a high-rise building in the center were measured using a wind tunnel. Not only the time-averaged velocity field, but also the tu…