Some features of modeling spectral characteristics of flow in boundary layer wind tunnels

The present study concerns with the spectral description of the atmospheric boundary layers (ABLs) for appropriate modeling for studying the wind effects on structures. By fitting a functional spectral form to the measured wind velocity data obtained in wind tunnel (WT) as well as in nature, it is shown that the Fichtl-McVehil form of spectrum fits better. The estimation of spectral parameters like turbulence intensities, integral length scales and small scales of wind velocity and their influence on the geometric scale (or time scale) are discussed. It is concluded that proper estimation of the spectral parameters of the simulated ABLs and their variation along the height of WT help in comparing the results obtained from different sources (WT tests) for identifying the influences of various flow/body parameters on the wind-induced effects and for formulating improved modeling of wind-structure interactions.