A numerical study on the wake behind a wind turbine is carried out focusing on determining the length of the near-wake based on the instability onset of the trailing tip vortices shed from the turbine blades. The numerical model is based on large-eddy simulations (LES) of the Navier-Stokes equations using the actuator line (ACL) method. The wake is perturbed by applying stochastic or harmonic e...

In the present research, the Wind Turbine placement problem for renewable energy utilization is solved using a viral systems optimization algorithm which finds the optimum configuration of wind turbines within a wind farm considering uniform wind-speed, and unidirectional wind. The problem is solved using a single type of turbine and constraining the available space to a flat scenario with a sq...

In the present study, an experimental study was conducted to characterize the formation and the evolution of the helical tip vortices and turbulent flow structures in the wake of a horizontal axis wind turbine model placed in an atmospheric boundary layer wind. A high-resolution particle image velocimetry system was used to make detailed flow field measurements to quantify the time evolution of...

This article presents a wind plant control strategy that optimizes the yaw settings of wind turbines for improved energy production of the whole wind plant by taking into account wake effects. The optimization controller is based on a novel internal parametric model for wake effects called the FLOw Redirection and Induction in Steady-state (FLORIS) model. The FLORIS model predicts the steady-st...

One well-known obstacle facing most sources of renewable energy is the significantly decreased energy density with respect to fossil fuels. Energy density of wind power is further penalized by the need for wind turbines to be spaced far enough apart to not interfere with one another. Conventional horizontal axis wind turbines (HAWTs) must be spaced far apart [3–5 turbine diameters in the crossw...

This paper briefly describes the implementation of a coupled near and far wake model for wind turbine rotor induction in the aeroelastic code HAWC2 and its application for flutter analysis of the NREL 5 MW wind turbine. The model consists of a far wake part based on Blade Element Momentum (BEM) theory, which is coupled with Beddoes’ near wake model for trailed vorticity. The first part of this ...

To investigate the aerodynamic characteristics of an Archimedes spiral wind turbine for urban-usage, both experimental and numerical studies were carried out. The Archimedes spiral blade was designed to produce wind power using drag and lift forces on the blade together. Instantaneous velocity fields were measured by two-dimensional PIV method in the near field of the blade. Mean velocity profi...

An experimental study was conducted to investigate the aeromechanic performance and near wake characterstics of dual-rotor wind turbine (DRWT) models with co-rotating or counter-rotating configurations in comparison to a conventional single rotor wind turbine (SRWT) model in order to elucidate the underlying physics to explore/optimize design of wind turbines for higher power yield and better d...

Wind is one of the most promising sources of alternative energy. The construction of wind farms is destined to grow in the U.S., possibly twenty-fold by the year 2030. To maximize the wind energy capture, this paper presents a model for wind turbine placement based on the wind distribution. The model considers wake loss, which can be calculated based on wind turbine locations, and wind directio...

The paper describes an observer capable of detecting the impingement on a wind turbine rotor of the wake of an upstream machine. The observer estimates the local wind speed and turbulence intensity on the left and right parts of the rotor disk. The estimation is performed based on blade loads measured by strain gages or optical fibers, sensors which are becoming standard equipment on many moder...