Simulation and Analysis of Atmospheric Boundary Layer Characteristics in a Wind Tunnel Using Python
Abstract
The simulation of atmospheric boundary layer flow in wind tunnels plays a very important role in the field of wind engineering for estimating the wind-induced loads on the structures. Despite the widespread use of the theoretical and empirical atmospheric boundary layer models, the applicability and the accuracy under a controlled wind tunnel conditions require a systematic validation using the experimental data. The primary objective of the present study is to experimentally evaluate and validate the commonly used atmospheric boundary layer characteristics and turbulence models using the wind tunnel measurements and a Python-based data analysis. The experiments were conducted in an Atmospheric Boundary Layer Wind Tunnel to replicate the turbulence characteristics of the open terrain conditions. Time-series velocity data obtained at multiple heights were processed using a dedicated Python framework to extract the key atmospheric boundary layer parameters viz. including roughness length, power-law exponent, turbulence intensity, turbulence length scales, probability density functions, and the wind spectra. The normalized mean velocity profiles were compared with the logarithmic and power-law formulations. Whereas the measured power spectra were compared against the theoretical von Karman spectrum. The results have shown a good agreement between wind tunnel measurements and the well-established theoretical and empirical models. The variations in the normalized velocity profiles, turbulence intensity, probability density functions, and the reduced power spectra with the height has been systematically presented. The study has confirmed the suitability of the wind tunnel experiments combined with the Python-based post-processing for the validation of the ABL flow characteristics and has provided a reproducible framework for the future experimental and numerical ABL investigations.
