Effects of architectural shapes on surface wind pressure distribution: Case studies of oval-shaped tall buildings

Natural ventilation has been an important strategy for the improvement of indoor air quality and human thermal comfort, and the reduction of energy consumption of buildings. Many investigations have been conducted to examine the natural ventilation of low, multi-rise buildings rather than tall buildings. Starting from enlarging the wind pressure difference to create wind-driven natural ventilation, this paper aims to analyze characteristics of surface pressure coefficients over tall buildings and to identify the influence of building shapes on coefficient distribution. Taking oval-shaped high-rise buildings as examples, this paper numerically investigated the effects of height-width ratio (HWR) and height-thickness ratio (HTR) on mean wind pressure coefficients (Cm) of building surfaces. Results indicated that windward side of oval-shaped buildings suffered from positive wind pressure, while side, top and back surfaces were basically in negative pressure areas. The absolute values of Cm on building surfaces increased as the decrease of HWR. On the contrary, Cm near central axis of side surfaces showed opponent trend due to fluid separation. In HTR scenario, Cm on windward and top surfaces were greatly affected, increasing along the HTR values. However, with the decrease of HTR, properties of wind field on leeward surface changed. Through this work, the architects and HVAC engineers can get a master plan of in which place they can set possible openings for the creation of possible ventilation paths.