In a wind farm, the upstream wind turbine may cause power loss to the downstream wind turbines due to the wake effect. Meanwhile, the energy production is determined by the power generation and the lifetime of the wind turbine. In this paper, an optimal active power control method is proposed to maximize the energy production of wind farms by considering the wake effect and the lifetime of wind...

Wind turbines are typically operated to maximize their own performance without considering the impact of wake effects on nearby turbines. There is the potential to increase total power and reduce structural loads by properly coordinating the individual turbines in a wind farm. The effective design and analysis of such coordinated controllers requires turbine wake models of sufficient accuracy b...

The actuator line technique was introduced as a numerical tool to be employed in combination with large eddy simulations to enable the study of wakes and wake interaction in wind farms. The technique is today largely used for studying basic features of wakes as well as for making performance predictions of wind farms. In this paper, we give a short introduction to the wake problem and the actua...

In this study, large-eddy simulations (LESs) were performed to investigate the effects of changing wind direction on the turbine wakes and associated power losses in the Horns Rev offshore wind farm. In the LES framework, the turbulent subgrid-scale stresses are parameterized using a tuning-free Lagrangian scale-dependent dynamic model, and the turbine-induced forces are computed using a dynami...

The proposed DOE/Sandia Scaled Wind Farm Technology Facility (SWiFT) hosted by Texas Tech University at Reese Technology Center in Lubbock, TX, will provide a facility for experimental study of turbine-turbine interaction and complex wind farm aerodynamics. This document surveys the current status of wind turbine wake and turbine-turbine interaction research, identifying knowledge and data gaps...

Title of dissertation: DEVELOPMENT OF A TIME-ACCURATE VISCOUS LAGRANGIAN VORTEX WAKE MODEL FOR WIND TURBINE APPLICATIONS Sandeep Gupta, Doctor of Philosophy, 2006 Dissertation directed by: Minta Martin Professor J. Gordon Leishman, Department of Aerospace Engineering A second-order accurate model has been developed and validated for modeling the unsteady aerodynamics of a wind turbine. The free...

Two different inverse design approaches are proposed for developing wind turbine blades for sub-scale wake testing. In the first approach, dimensionless circulation is matched for full scale and sub-scale wind turbine blades for equal shed vorticity in the wake. In the second approach, the normalized normal and tangential force distributions are matched for large scale and small scale wind turb...

An experimental study was performed to examine the wake characteristics and aeromechanic performance of an innovative twin-rotor wind turbine (TRWT) in comparison with those of a conventional single-rotor wind turbine (SRWT). The comparative study was conducted in a large-scale Aerodynamic/Atmospheric Boundary Layer (AABL) wind tunnel with the TRWT and SRWT model sited in simulated atmospheric ...

Field measurements of the wake flow produced from a 2-MW Enercon E-70 wind turbine were performed using three scanning Doppler wind lidars. A GPS-based technique was used to determine the position of the wind turbine and the wind lidar locations, as well as the direction of the laser beams. The lidars used in this study are characterized by a high spatial resolution of 18 m, which allows the de...

An experimental study is conducted to characterize the dynamic wind loads and evolution of the turbulent vortex and flow structures in the wake of a horizontal axis wind turbine (HAWT). In addition to measuring dynamic wind loads (both aerodynamic forces and moments) acting on a wind turbine model, a high-resolution Particle Image Velocimetry (PIV) system was used to make “free-run” and phase-l...