Individual wind turbines, whether stand alone or in a wind farms, typically operate to maximize their own production without considering the impact of wake effects on nearby turbines. Investigation into wind turbine interaction within a wind farm has the potential to increase total power and reduce structural loads by properly coordinating the individual turbines that comprise the wind farm. To...

Modelling of wind farms using computational fluid dynamics (CFD) resolving the flow field around each wind turbine’s blades on a moving computational grid is still too costly and time consuming in terms of computational capacity and effort. One strategy is to use sub-models for the wind turbines, and sub-grid models for turbulence production and dissipation to model the turbulent viscosity accu...

The Reynolds Stress Model (RSM) is adopted to simulate the wind turbine wake and the simulation results are compared with the wind tunnel test data, simulation results from the standard k-ε model and a modified k-ε model. RSM shows good performance in predicting the turbine wakes velocity, turbulence intensity and the kinetic shear stress, while the k-ε based models fail to predict either wakes...

Measurements have been made in the wake of a model wind turbine in both a weakly unstable and a baseline neutral atmospheric boundary layer, in the EnFlo stratified-flow wind tunnel, between 0.5 and 10 rotor diameters from the turbine, as part of an investigation of wakes in offshore winds. In the unstable case the velocity deficit decreases more rapidly than in the neutral case, largely becaus...

This experimental study was conducted in a wind tunnel using two turbines in tandem arrangement and downstream turbine is located at X/D=2. The purpose was to investigate how yawing the upstream turbine will affect the performance of the downstream turbine as well as the upstream turbine. Wind loading (thrust force), rotational frequency and power output are the parameters used to define the pe...

Wind-profiling lidars are now regularly used in boundary-layer meteorology and in applications such as wind energy and air quality. Lidar wind profilers exploit the Doppler shift of laser light backscattered from particulates carried by the wind to measure a line-of-sight (LOS) velocity. The Doppler beam swinging (DBS) technique, used by many commercial systems, considers measurements of this L...

It is known that wind turbines actually operate in the lower part of the atmospheric 11 boundary layer (ABL), the modelling of this ABL flow is an important precondition for the 12 simulations of wind turbine wakes. So, the capabilities of various inlet boundary conditions with 13 related modelling methodologies in constructing equilibrium ABL are validated firstly through 14 cases of a neutral...

The objective of this study is to develop a model-free optimization algorithm to improve the total wind farm power production in a cooperative game framework. Conventionally, for a given wind condition, an individual wind turbine maximizes its own power production without taking into consideration the conditions of other wind turbines. Under this greedy control strategy, the wake formed by the ...

Operating horizontal axis wind turbines (HAWT) generate large-scale wake structures that can have considerable impact on downwind turbines. A HAWT exposed to vortices from upwind turbines generally produces reduced power and experiences increased structural vibrations that cause disproportionally accelerated material fatigue. Numerical simulation of the turbulent flow field is a viable approach...

Abstract. In this paper, we present a novel control-oriented model for predicting wake effects in wind plants, called the FLOw Redirection and Induction Dynamics (FLORIDyn) model. The model predicts the wake locations and the effective flow velocities at each turbine, and the resulting turbine electrical energy productions, as a function of the control degrees of freedom of the turbines (the ax...