Influence of built form in urban ventilation assessment of tropical cities with weak wind conditions

Abstract

Urban ventilation is recognized as effective countermeasure on air pollution and urban heat island, yet most tropical urban areas receive low annual mean wind velocity thus lessening potential for urban ventilation. Effect of built form on resulting mean wind velocity at pedestrian-level was analyzed through computational fluid dynamics (CFD) to assess effectiveness in urban ventilation of tropical cities with weak wind conditions based on three heterogeneous built form of Kampung Baru, Taman Keramat and Pantai Dalam which located in the city of Kuala Lumpur for wind direction from south and west. The urban density for the built form was characterized by using urban packing density parameter of frontal area ratio, ?f and the urban ventilation was assessed based on availability of pedestrian wind which described using wind velocity ratio, VR. Influence of built form in urban ventilation was found to be significant in affecting the mean wind velocity, where magnitude of VR at pedestrian-level was decreasing as the value of ?f of the built form increases. Suggestions to improve urban ventilation design in major development project are provided based on these findings.