Experiments on the wind tunnel simulation of atmospheric boundary layers

The simulation of atmospheric boundary layers using spires, a barrier wall, and a fetch of roughness elements is discussed in the light of experiments carried out to reproduce the characteristics of a boundary layer for urban terrain conditions. Comparisons of wind tunnel and atmospheric data are presented, including mean-velocity profiles, turbulence intensities, turbulence spectra, and turbulence length scales, in particular integral and inertial subrange scales. The selection of model scales is discussed. The experimental errors in the evaluation of Reynolds and wall shear stresses, roughness lengths, and integral length scales are analyzed, together with their effect on model scale values.