modelWindProfilePowerLaw

Wind profile power law relationship of Hellmann

Information

This model contains the wind profile power law relationship of Hellmann.

The power law allows for the calculation of wind speeds at different heightghts based on the reference speed and heightght.

Roughness class	Roughness length / m	Land cover types
0	0.0002	Water surfaces: seas and Lakes
0.5	0.0024	Open terrain with smooth surface, e.g. concrete, airport runways, mown grass etc.
1	0.03	Open agricultural land without fences and hedges; maybe some far apart buildings and very gentle hills
1.5	0.055	Agricultural land with a few buildings and 8 m high hedges seperated by more than 1 km
2	0.1	Agricultural land with a few buildings and 8 m high hedges seperated by approx. 500 m
2.5	0.2	Agricultural land with many trees, bushes and plants, or 8 m high hedges seperated by approx. 250 m
3	0.4	Towns, villages, agricultural land with many or high hedges, forests and very rough and uneven terrain
3.5	0.6	Large towns with high buildings
4	1.6	Large cities with high buildings and skyscrapers

Hau, E. (2016). Windkraftanlagen: Grundlagen, Technik, Einsatz, Wirtschaftlichkeit (6. Auflage). Springer Vieweg.

Type	Name	Default	Description
Modelica.Units.SI.Height	height		Height of the wind speed to calculate
Modelica.Units.SI.Height	heightRef	10	Reference height of the known wind speed
Modelica.Units.SI.Length	lenRuf	0.6	Roughness length
Real	cof	1/log(height/lenRuf)	Hellmann exponent (coefficient)

Type	Name	Default	Description
Modelica.Blocks.Interfaces.RealInput	winSpeRef		Wind speed at the reference height
Modelica.Blocks.Interfaces.RealOutput	winSpe		Wind speed at height