Gust structure and generation in canopy flows

Authors: Segalini, A. S., Fransson, J. H. M., Dahlberg, J.Å., Alfredsson, P.H.
Document Type: Article
Pubstate: Unknown
Journal: EWEA conference, Brussels, Belgium, March 14-17 2011
Year: 2011


Due to an increased demand to place wind tur- bines in forest areas it is of importance to know the details of the wind flow field over forest canopies. In this study we compare the flow characteristics of an atmospheric boundary layer over a forest canopy and a wind tunnel canopy model. Both the mean velocity distribution and the turbulence intensities were measured for both cases and the friction velocity was determined from the Reynolds shear stress above the edge of the canopy. The comparison between the two data sets is reason- ably good, especially close to the canopy edge. The analysis of the time series of both mea- surement sets has highlighted that the turbulent canopy flow (in both wind tunnel and atmospheric data sets) is composed, beside the high frequency turbulence, by some flow structures detectable only through phase averages approaches.