Numerical Simulation of Outdoor Air Flow and Ventilation Performance around an Array of Buildings

Abstract

This study examines outdoor air flow and ventilation around an array of buildings by parameterizing the separation distance (W) between the frontal column of buildings and the rest of the building array. The aim was to assess the impact of the separation distance on the air ventilation performance. The study was set around a neighbourhood of Kuala Lumpur, the Capital City of Malaysia, and employs the numerical simulation technique utilizing the Reynolds-Averaged Navier-Stokes equations. The full-scale size models of common building configurations and weather data around the City were utilized to calculate the mean wind field around the building array. The air ventilation performance was evaluated in terms of air velocity ratio (VR) and air flow rate (AFR). Results indicate that the invigoration of the flow in the lateral streets is mostly due to corner-stream inflow into the streets through the side-openings. The VR was found to increase with increase in the separation distance and this was found to be due to corner-stream inflow into the streets. The increase in VR ranged between 15% and 60% between the values at W = 12 m and W = 36 m. The results demonstrate the existence of an optimal location of the frontal column of buildings in a building array that would invigorate the outdoor air flow and improve human thermal comfort.