Numerical Simulation of the Interference Effects to Outdoor Air Flow and Ventilation around Adjacent Building Arrays

Abstract

The study examines the wind environment at the pedestrian level between two building arrays to determine the effect of the longitudinal separation distance (W) between the arrays of buildings for different height ratios (HR) of the arrays, on the outdoor air flow and ventilation, and provide a passive strategy of engendering higher wind motion and ventilation necessary for thermal comfort and human health. The study predicts the mean wind field around the arrays of buildings using the technique of numerical simulation. Results show that the ventilation performance strongly depends on the separation distance through the frontal and corner-stream inflows. The corner-stream flow was found to be able to account for about 50% of the total inflow. The optimum separation distances obtained for building configurations with HR = 1, HR = 1.5 and HR = 2, were respectively, W=12 m, W=30 m, and W=36 m. The increase in velocity ratio for these configurations ranges between 14% and 50%. The findings demonstrate that the separation distance between adjacent building arrays can be used to substantially increase the air motion and ventilation around building clusters and that corner-stream flow plays a very significant role in achieving the flow invigoration.