An experimental study was conducted to investigate on the effects of the relative rotation directions of two tandwm wind turbines on the power production performance and flow characteristics in the wakes of two wind turbines in tandem. The experimental study was performed in a large-scale Aerodynamics/tmospheric Boundary Layer (AABL) Wind Tunnel located at the Aerospace Engineering Department o...

The stratification of the atmospheric boundary layer (ABL) is classified in terms of the M-O length and subsequently used to determine the relationship between ABL stability and the fatigue loads of a wind turbine located inside an offshore wind farm. Recorded equivalent fatigue loads, representing blade-bending and tower bottom bending, are combined with the operational statistics from the ins...

We investigate the use of optimal coordinated control techniques in large eddy simulations of wind farm boundary layer interaction with the aim of increasing the total energy extraction in wind farms. The individual wind turbines are considered as flow actuators, and their energy extraction is dynamically regulated in time, so as to optimally influence the flow field. We extend earlier work on ...

The actuator disc-RANS model has widely been used in wind and tidal energy to predict the wake of a horizontal axis turbine. The model is appropriate where large-scale effects of the turbine on a flow are of interest, for example, when considering environmental impacts, or arrays of devices. The accuracy of the model for modelling the wake of tidal stream turbines has not been demonstrated, and...

Large Eddy Simulations (LES) are carried out using OpenFOAM to investigate the canopy created velocity inflection in the wake development of a large wind turbine array. Simulations are performed for two cases with and without forest separately. Results of the simulations are further compared to clearly show the changes in the wake and turbulence structure due to the forest. Moreover, the actual...

An aerodynamic fairing can reduce the effects of the wind turbine tower wake on the blades of a downwind rotor. Previous studies on fairing design have focused on idealized conditions and time-averaged drag reductions, whereas this is the first study to obtain and analyze unsteady velocity field data in the wake of minimum drag fairings at non-zero angles of attack, specifically designed for wi...

The classical momentum solution for the optimum induced-flow distribution of a wind turbine in the presence of wake swirl can be found in many textbooks. This standard derivation consists of two momentum balances (one for axial momentum and one for angular momentum) which are combined into a formula for power coefficient in terms of induction factors. Numerical procedures then give the proper i...

When studying flow phenomena in a scaled laboratory experiment or in a computational simulation, it is often not possible to achieve dynamic similarity with the fullscale flow of interest. In the case of wind and water turbine experiments, a scaled model turbine may not perform as well as in the field, or perhaps not at all, due to a mismatch of Reynolds number and other scaling difficulties su...

This paper presents a novel mixed integer linear programing (MILP) formulation for finding the optimal layout of a fixed number of identical turbines that maximizes wind farm power generation. Previous MILP formulations with power maximizing objectives discretize the feasible space by using a grid of possible turbine locations. The proposed MILP formulation takes a different approach by allowin...

This work is mainly dedicated to the study of the characteristics of spectral coherence of turbulence fluctuations in wind turbine wakes. A computational fluid dynamics (CFD) code has been implemented using a large-eddy simulation (LES) approach, which is thought to be conceptually more suitable for studying the turbulence evolution in a wind turbine wake. Comparisons with experimental data fro...