Improved Experimental Simulation of Wind Characteristics around Tall Buildings

A wind-tunnel study has been carried out to investigate the effects of the barrier wall and surface roughness on the simulated atmospheric boundary-layer (ABL) flow generated using the Counihan method, (i.e., the castellated barrier wall, vortex generators, and surface roughness elements). Experimental results indicate that changing the basic barrier height does not influence the mean-velocity profiles. However, turbulence intensity and absolute values of the Reynolds stress increase with an increase in the barrier height, and simultaneously the integral length scales of turbulence decrease. Variations in the height of the barrier castellation influence the simulated ABL flow similarly to the changes in the basic barrier height. Empirical relations were derived to quantify effects of the surface roughness height on the simulated ABL flows. Increasing the height of surface roughness elements results in a larger velocity defect and stronger turbulence in the near-ground region. DOI: 10.1061/(ASCE)AS.1943-5525.0000167. (C) 2012 American Society of Civil Engineers.