Statistical analysis of turbulent flow over a building array using LES

Understanding the turbulent flow feature over building arrays are essential because the flow distribution is determined by the interaction between the atmospheric boundary layer and building array. The present study investigated the turbulent statistics over roughness elements arranged in a staggered array using large eddy simulation. Unlike a conventional method to drive the flow by the constant pressure gradient, the current simulation method employed a vertical profile of the streamwise pressure gradient determined by the experimental data of the Reynolds stress obtained in a wind tunnel. The time series data were analyzed to determine the fundamental statistics and probabilistic characteristics. The results revealed that the probability density function of the streamwise velocity component followed the gaussian distribution curve behind the building model. However, the probability density function of the vertical component showed a positive skewed results owing to the reverse flow back to the roughness element.