高层建筑烟囱效应及风压联合作用的模拟研究

Numerical Simulation Research on Combined Wind and Stack Effects of a Super High-rise Building

采用多区域网络模型数值模拟方法,结合风洞试验和CFD数值模拟结果,对一栋340 m超高层建筑的烟囱效应及风压联合作用问题进行了模拟分析.研究发现:1)纯烟囱效应导致的建筑内部电梯与室外压差曲线为线性分布,符合理论分布规律;随风速增大,电梯与室外压差分布逐渐受到风压主导,压差分布曲线由线性转向非线性,风速越大效应越显著.2)建筑中性面位置受风速影响较小,密闭性较差的避难层对避难层电梯以及上下层电梯的压差分布影响明显.3)不同风向对烟囱效应压差表现出不同的作用:在冬季高频风向ENE下,整体上风压抑制热压;而在风向为N时,风压增强热压;在夏季高频风向ESE下,避难层以外楼层风压抑制热压,避难层风压增强热压.4)提高幕墙密封等级及增加电梯前室门阻隔单元等措施,可有效缓解烟囱效应过大压差.

The multi-zone network model method,together with the wind tunnel test and CFD numerical simulation results,was employed to simulate the combined wind and stack effects of a high rise building with the height of 340 m.It was concluded that:1)The differential pressure curves between the indoor elevator and outdoor were linear under pure stack effect,which were consist with the theoretical result.The differential pressure between the indoor elevator and outdoor was gradually dominated by the wind effect with the increase of wind speed,and its curve gradually changed from linear distribution to nonlinear distribution.Higher wind speed would lead to significant nonlinear feature.2)The neutral plane level of the building was hardly affected by the outdoor wind speed,and the refuge floors had great influences on the differential pressure elevators on the refuge floor and its neighboring floors;3)Different wind on different seasons would have different impacts on the stack pressures.For one high frequency ENE wind in winter,the wind pressure would depress the stack pressure generally,while for another N wind,the wind pressure would strengthen the stack pressure by contrast.Under the ESE wind in summer,the wind pressure would depress the stack pressure on the floors except for the refuge floor,while an opposite effect would occur on the refuge.4)Measures such as improving the sealing level of the glass curtain and/or adding additional partitions were helpful to mitigate the excessive differential pressure caused by stack effect.