[en] Generating atmospheric turbulence in wind tunnels is an important issue in the study of wind turbine aerodynamics. A turbulent inlet is usually generated using
passive grids. However, to obtain an atmospheric-like flow field relatively large length scales (L~30 cm) and high turbulence intensities (I~15%) need to be
reproduced. In this work, the passive grid technique has been used in combination with a downstream expansion test section in order to investigate the generation of
atmospheric like turbulence, with the possibility of varying both the turbulence intensity and the integral length scale of the flow field independently. Four passive
grids with different mesh and bar sizes were used with four wind velocities and five downstream measurement positions. It was found that the flow field is isotropic
and homogeneous for distances less than what is recommended in literature (x=M 5). The effect of the expansion on the turbulence characteristics is also investigated
in detail for the first time. The study confirms that by adding an expansion test section it is possible to increase both turbulence intensity and integral length
scale downstream from the grid with limited impact on the overall flow quality in terms of anisotropy and energy spectra.
Disciplines :
Civil engineering Energy Aerospace & aeronautics engineering
Author, co-author :
Vita, Giulio; University of Birmingham
Hemida, Hassan; University of Birmingham
Andrianne, Thomas ; Université de Liège - ULiège > Département d'aérospatiale et mécanique > Interactions Fluide-Structure - Aérodynamique expérimentale
Baniotopoulos, Charalampos C.; University of Birmingham
Language :
English
Title :
Generating atmospheric turbulence using passive grids in an expansion test section of a wind tunnel
Publication date :
15 February 2018
Journal title :
Journal of Wind Engineering and Industrial Aerodynamics
ISSN :
0167-6105
eISSN :
1872-8197
Publisher :
Elsevier, Netherlands
Volume :
177
Pages :
1-14
Peer reviewed :
Peer Reviewed verified by ORBi
European Projects :
H2020 - 643167 - AEOLUS4FUTURE - Efficient harvesting of the wind energy
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