000022601 001__ 22601
000022601 005__ 20170724144656.0
000022601 04107 $$aeng
000022601 046__ $$k2017-07-04
000022601 100__ $$aCheynet, Etienne
000022601 24500 $$aMeasurements of low-frequency wind spectral properties relevant to design of long-span bridges

000022601 24630 $$n7.$$p7th European and African Conference on Wind Engineering 
000022601 260__ $$bl'Association pour l'Ingénierie du Vent
000022601 506__ $$arestricted
000022601 520__ $$2eng$$aThe present paper investigates the capability of synchronized long-range Doppler wind lidars to capture the wind coherence at scanning distances up to 4.5 km. The data set considered comes from a field measurement campaign conducted from May 2016 to June 2016 in the Bjørnafjord (Norway). The longrange WindScanner system deployed consisted of three lidar units in a combination of fixed and “dynamic” Line-Of-Sight (LOS) scanning modes. In the latter configuration, the horizontal wind components were retrieved at four different locations with a sampling frequency of at least 0.25 Hz. The data are used to estimate the lateral coherence of the along-wind component for wind velocities ranging from 6 m s−1 to 14 m s−1 and lateral separations from 18 m to 177 m. Although the spatial averaging was not observed to have any significant influence on the coherence estimates, the decay coefficient measured using a simple exponential co-coherence function was larger than expected for the along-wind component and lateral separations, with values around 23 for 10 m s−1 ≤ u ≤ 14 m s−1 . The apparent predominance of stable stratification and the large scanning distances associated with large cross-wind separations may contribute to a measured coherence lower than predicted in the Norwegian handbook N400. Although the dominant wind direction was from North-West during the measurement period, a larger variety of wind directions with different properties are expected. For a more complete analysis, a wider range of wind directions and stronger wind velocities are desirable.

000022601 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000022601 653__ $$aWind coherence; Long-range lidar; multi-lidar; Full-scale measurements

000022601 7112_ $$a7th European and African Conference on Wind Engineering$$cLiège, BE$$d2017-07-04 / 2017-07-07$$gEACWE2017
000022601 720__ $$aCheynet, Etienne$$iSnaebjörnsson, Jónas Thór$$iJakobsen, Jasna Bogunović
000022601 8560_ $$ffischerc@itam.cas.cz
000022601 8564_ $$s629013$$uhttps://invenio.itam.cas.cz/record/22601/files/150.pdf$$yOriginal version of the author's contribution in proceedings, id 150, section .
000022601 962__ $$r22493
000022601 980__ $$aPAPER