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VestasFOAM

Since late 2009, Vestas has switched focus from commercial CFD packages to in-house CFD development using the OpenFOAM CFD toolkit [1]. This has resulted in the VestasFOAM process which is currently deployed globally within the company and used in thousands of micro-siting wind resource assessment projects to date.

Latest version

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.

Software
Solver
OpenFOAM
License
Regime
Turbulence
Turbulence closure
Turbulence model

k-epsilon [2] turbulence closure with Durbin limiter [4]

Atmospheric boundary layer
Range
Coriolis
Yes
Atmospheric Stability
Atmospheric Stability
Yes
Stability model
Boussinesq approximation with appropriate terms added to the k-epsilon model.
Canopy
Forest canopy
Yes
Canopy model
As described in Sanz [5]
Wind farm
Wind turbine
Yes
Rotor model
Additional information

Rotor/wake models are currently being evaluated for full-time integration into the automated VestasFOAM process.

References

[1] OpenFOAM CFD Toolkit - www.openfoam.com

[2] Jones, W. P., and Launder, B. E. (1972), "The Prediction of Laminarization with a Two-Equation Model of Turbulence", International Journal of Heat and Mass Transfer, vol. 15, 1972, pp. 301-314.

[3] Richards, P.J. and Hoxey, R.P., 1993. Appropriate boundary conditions for computational wind engineering models
using the k-ε turbulence model. Journal of Wind Engineering and Industrial Aerodynamics, 46 & 47, 145-153.

[4] Durbin, P. A. (1996), "On the k-epsilon Stagnation Point Anomaly", International Journal of Heat and Fluid Flow, 1996, Vol. 17, pp. 89-90.

[5] Sanz, C. 2003 A note on k−ε modelling of vegetation canopy air-flows. Boundary-Layer Meteorology 108, pp. 191–197.

[6] Pointwise Inc. - www.pointwise.com

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Public