Wind Energy

18.6 Concluding Remarks
18 Boundary-Layer Influence on Extreme Events 109
The velocity field up- and downstream of the obstacle has been measured
in the laboratory. Contrary to the influence of the on-obstacle slip condition,
the after-obstacle slip condition has no major dynamical effect on the
flow field. The boundary-layer separation on the obstacle is wave-induced and
leads to TLW with embedded rotors. The wave field also appears to control
the boundary-layer thickness, independently of the Re-number. Given these
results, if the wind-field – including its direction – near the ground and at
higher altitudes is to be correctly predicted, the no-slip condition is necessary
to be used up to at least the location of the first half internal-wave length.
Acknowledgement
We thank the SPEA team of Météo-France for its strong implication and the
PATOM program for its financial support.
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