Pauscher, L; Callies, D; Klaas, T; Foken, T: Wind observations from a forested hill: Relating turbulence statistics to surface characteristics in hilly and patchy terrain, Meteorologische Zeitschrift, 27(1), 43-57 (2018), doi:10.1127/metz/2017/0863

This study investigates turbulence characteristics as observed at a 200m tall mast at a hilly and complex site. It thereby concentrates on turbulence statistics, which are important for the site suitability analysis of a wind turbine. The directional variations in terrain are clearly reflected in the observed turbulence intensities and drag. Integral turbulence statistics showed some variations from their typical flat terrain values. Footprint modelling was used to model the area of effect and to relate the observed turbulence characteristics to the ruggedness and roughness within the estimated fetch area. Among the investigated turbulence quantities, the normalised standard deviation of the wind velocity along the streamlines showed the highest correlation with the effective roughness and ruggedness within the footprint followed by the normalised friction velocity and normalised standard deviation of the vertical wind speed. A differentiation between the effects of roughness and ruggedness was not possible, as forest cover and complex orography are highly correlated at the investigated site. An analysis of turbulence intensity by wind speed indicated a strong influence of atmospheric stability. Stable conditions lead to an overall reduction in turbulence intensity for a wind speed range between approx. 6–12m s−1 when compared to neutral stratification. The variance of the horizontal wind speed strongly varied over the height range which is typical for a modern wind turbine and was in the order of the differences between different standard turbulence classes for wind turbines.

Aktuelle Termine

Do. 21.06.2018
The tangled evolutionary history of plants and fungi
Mo. 25.06.2018
Öffentliche Vorträge im Rahmen der Besetzung der Professur "Sportökologie"
Geographisches Kolloquium:
Di. 19.06.2018 aktuell
Land/water use management of wetlands of Lakes Haramaya and Zwai and their watersheds: A crossroad between development, sustainability and climate change?
Ökologisch-Botanischer Garten:
Mi. 20.06.2018
Botanische Mittagspause
Mi. 27.06.2018
Harmlos bis tödlich: Krankheiten der Bäume
Wetter Versuchsflächen
Luftdruck (356m): 976.7 hPa
Lufttemperatur: 23.1 °C
Niederschlag: 0.0 mm/24h
Sonnenschein: <1 h/d
Wind (Höhe 17m): 9.5 km/h
Wind (Max.): 16.9 km/h
Windrichtung: W

Globalstrahlung: 122 W/m²
Lufttemperatur: 19.6 °C
Niederschlag: 0.0 mm/24h
Sonnenschein: 3 h/d
Wind (Höhe 32m): 5.8 km/h
Wind (Max.): 12.5 km/h