TY - JOUR
T1 - Application of short-range dual-Doppler lidars to evaluate the coherence of turbulence
AU - Cheynet, Etienne
AU - Jakobsen, Jasna Bogunović
AU - Snæbjörnsson, Jónas
AU - Mikkelsen, Torben
AU - Sjöholm, Mikael
AU - Mann, Jakob
AU - Hansen, Per
AU - Angelou, Nikolas
AU - Svardal, Benny
N1 - Funding Information: The study was initiated and performed with the support from the Norwegian Center for Offshore Wind Energy (NORCOWE, Project Number 193821 supported by the Research Council Norway). Support by the Norwegian Public Road Administration on the long-term wind and response monitoring of the Lysefjord bridge, as well as the assistance during the measurement campaign, is also acknowledged. Publisher Copyright: © 2016, Springer-Verlag Berlin Heidelberg.
PY - 2016/12/1
Y1 - 2016/12/1
N2 - Two synchronized continuous wave scanning lidars are used to study the coherence of the along-wind and across-wind velocity components. The goal is to evaluate the potential of the lidar technology for application in wind engineering. The wind lidars were installed on the Lysefjord Bridge during four days in May 2014 to monitor the wind field in the horizontal plane upstream of the bridge deck. Wind records obtained by five sonic anemometers mounted on the West side of the bridge are used as reference data. Single- and two-point statistics of wind turbulence are studied, with special emphasis on the root-coherence and the co-coherence of turbulence. A four-parameter decaying exponential function has been fitted to the measured co-coherence, and a good agreement is observed between data obtained by the sonic anemometers and the lidars. The root-coherence of turbulence is compared to theoretical models. The analytical predictions agree rather well with the measured coherence for the along-wind component. For increasing wavenumbers, larger discrepancies are, however, noticeable between the measured coherence and the theoretical predictions. The WindScanners are observed to slightly overestimate the integral length scales, which could not be explained by the laser beam averaging effect alone. On the other hand, the spatial averaging effect does not seem to have any significant effect on the coherence.
AB - Two synchronized continuous wave scanning lidars are used to study the coherence of the along-wind and across-wind velocity components. The goal is to evaluate the potential of the lidar technology for application in wind engineering. The wind lidars were installed on the Lysefjord Bridge during four days in May 2014 to monitor the wind field in the horizontal plane upstream of the bridge deck. Wind records obtained by five sonic anemometers mounted on the West side of the bridge are used as reference data. Single- and two-point statistics of wind turbulence are studied, with special emphasis on the root-coherence and the co-coherence of turbulence. A four-parameter decaying exponential function has been fitted to the measured co-coherence, and a good agreement is observed between data obtained by the sonic anemometers and the lidars. The root-coherence of turbulence is compared to theoretical models. The analytical predictions agree rather well with the measured coherence for the along-wind component. For increasing wavenumbers, larger discrepancies are, however, noticeable between the measured coherence and the theoretical predictions. The WindScanners are observed to slightly overestimate the integral length scales, which could not be explained by the laser beam averaging effect alone. On the other hand, the spatial averaging effect does not seem to have any significant effect on the coherence.
UR - https://www.scopus.com/pages/publications/84995809840
U2 - 10.1007/s00348-016-2275-9
DO - 10.1007/s00348-016-2275-9
M3 - Article
SN - 0723-4864
VL - 57
JO - Experiments in Fluids
JF - Experiments in Fluids
IS - 12
M1 - 184
ER -