Wind load characteristics of tall buildings under moving downburst
FANG Zhiyuan1, WANG Zhisong1,2, LI Zhengliang1,2, HUANG Hanjie3
1.School of Civil Engineering, Chongqing University, Chongqing 400045, China;
2.MOE Key Lab of New Technology for Construction of Cities in Mountain Area, Chongqing University, Chongqing 400045, China;
3.China Aerodynamics Research and Development Center, Mianyang 621000, China
Abstract:In order to study the wind load characteristics of high-rise buildings under moving downburst, a pressure test was carried out on a high-rise building model by using a movable impinging jet device, and the numerical simulation was carried out by using computational fluid dynamics (CFD) method. The distribution characteristics of wind pressure on the surfaces of high-rise building model at different locations in the wind field and the mechanism of wind load during the storm movement were analyzed. The results show that the wind speed of the front flank downburst will be strengthened and those of the rear flank downburst will be weakened by the storm movement, thus making the overall wind pressure on the building surface change accordingly. When the building is located on the center line of storm movement, the eddies formed by the separation of airflow mainly occur in the front of the windward side of the top surface and the upper corner of the windward side of the side surface. These areas have relatively large negative pressure, and the top surface of the building will generate relatively large positive pressure when the storm passes. When the building is located outside the center line of storm movement, the wind direction of high-rise buildings will change with the storm movement. When the building is located at the front flank downburst, the side surface with a smaller angle to the wind will appear a larger negative pressure area due to the separation of the air flow at the edge of the bluff body. When the building is located at the rear flank downburst, the corner area on the top of the building will have a larger negative pressure due to the conical vortex.
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