Actuator disk

WakeBlaster 2.0

Submitted by Wolfgang Schlez... on May 2, 2017 - 6:52pm
Main hypothesis

ProPlanEn developed this solver specifically for modelling the waked flow in wind farms.  WakeBlaster is a clould based calculation engine offered as SaaS. The software focuses on accurate modelling of the most important aspects of a wind turbine wake.  WakeBlaster's balance between computational performance and accuracy is targeted at industry users. As a 3D RANS solver it is modelling wake-wake and wake-ground interaction that is not well captured by current industry models. WakeBlaster is suitable for wind farms with a few to thousands  of turbines. WakeBlaster 2 refines modelling the waked flow under different stability conditions - now characterised by a flow case specific Monin-Obukhov Length.


Nicholas Robinson's picture
Submitted by Nicholas Robinson on May 12, 2016 - 4:09pm
Main hypothesis

Uses maximum of eddy-viscosity wake model and a boundary layer wake model at each turbine for each case or timestep.


Submitted by Roberto A. Chav... on May 27, 2015 - 12:00am
Main hypothesis

This model is formulated with the assumptions of isotropic eddy-viscosity turbulence and the k-ε two-equation closure scheme modified for atmospheric flows.

CFDWind1 deals with surface boundary layer (SBL) by imposing a set of coefficients as well as proper modifications to the boundary conditions (inlet boundary and wall functions) in order to comply with the Monin-Obukhov Similarity Theory (MOST) as proposed by Richards & Hoxey (1993) and Parente et al. (2011). 


Submitted by Jonas Schmidt on May 5, 2015 - 10:53am
Main hypothesis

12 RANS simulations of a uniform non-rotating actuator disk were carried out using OpenFOAM version 2.1.1, with k-e turbulence model including additional dissipation near the rotor, a la El-Kasmi and Masson 2008. These 12 simulations form a data base, from which the wake deficit data is interpolated at arbitrary inflow velocities at hub height. This way CFD simulations are used to define a numerical wake model. flapFOAM is a new wind farm modelling software that is currently in development at Fraunhofer IWES.

Windmodeller (Ansys-CFX)

Benjamin Martinez's picture
Submitted by Benjamin Martinez on May 5, 2015 - 10:49am
Main hypothesis

- Steady-state RANS for neutral simulations

- Accounts for atmospheric stability by adding an additional energy conversation equation formulated in terms of the potential temperature and using the k-epsilon closure scheme. Surface conditions are determined via heat flux or temperature gradient.

- Actuator Disk Modelling for Wakes


Daniel Cabezon's picture
Submitted by Daniel Cabezon on May 5, 2015 - 9:59am
Main hypothesis

The model derives from a previous elliptic model and it is inspired on the parabolic technique of other models such as UPMPARK and Windfarmer but using the actuator disk technique to represent the wind turbine instead of wind speed deficit. 

The wind turbine is represented as an actuator disk uniformly loaded. This means that the wind turbine acts as a sink of momentum, associated to the drag force exerted over the incoming flow. The reference wind speed for each disk is initially calculated from the wind speed at the position of the disk and corrected through the method proposed by Calaf

The solution algorithm consists of a decomposition of the domain into a finite number of adjacent subdomains that are solved sequentially in the axial direction, using the output of each subdomain as input for the next one. This is done until the end of the domain is reached. This way the computational time becomes significantly lower in comparison to the solution of a single domain by means of a purely elliptic approach.

VestasFOAM 1.1.0 - Steady

Submitted by Yavor Hristov on May 5, 2015 - 12:00am
Main hypothesis

The basis of VestasFOAM is built upon the simpleFoam solver distributed with the publically available OpenFOAM release and suitable for steady, incompressible, turbulent and isothermal flows. This solver and associated k-epsilon turbulence model [2] have been expanded to include appropriate boundary conditions for ABL flow [3], Coriolis force, Durbin realizability constraint [4], extension to stratified flows as wells as canopy [5] and buoyancy source terms. Meshes are automatically generated with Pointwise [6] using structured hyperbolic extrusion ensuring the highest possible quality. In order to reduce the mesh size, the horizontal mesh goes through a step-wise reduction in resolution with height once sufficiently away from the terrain. This creates a hybrid mesh with "hanging-node" type architecture maximizing efficiency without sacrificing mesh quality near the terrain and turbines.