镂空围屏对建筑物表面风压的影响

Effect of Pierced Enclosure on Wind Pressure on Building Surface

在建筑物的玻璃幕墙外安装镂空材料制成的围屏,会对其表面风压分布产生影响。风洞试验结果表明,镂空围屏的存在并不改变玻璃幕墙压力分布的基本形态,但压力值的大小会发生变化。相对而言,由于围屏改变了分离点位置,靠近围屏边缘部分的区域受到的影响更大。在55%的透气率的情况下,安装围屏后,幕墙表面的平均压力在迎风和发生流动分离时会降低10%左右,而当围屏处于背风区时,背压值反而略有增加。各种条件下,脉动压力都会因为围屏减弱了来流的脉动能量作用而降低10%左右。因此,总的来看安装镂空围屏将使玻璃幕墙偏于安全。

The pierced enclosure outside the glass curtain wall can affect the wind pressure on building surface. The results of wind tunnel test show that the basic pressure distributions on the glass curtain wall isn＇t changed, although the pressure value is affected by the additional pierced enclosure. It has significant influence on the region close to the edge of pierced enclosure due to the change of the position of flow separation. Under the condition of porosity 55 % , the average pressure is reduced by 10% when the pierced enclosure is on the windward side or in the region where flow separates; while the pressure is increased slightly when the pierced enclosure is on the lee side. The fluctuating pressure is reduced by 10% due to the weakening of turbulent energy by pierced enclosure. In conclusion, the pierced enclosure has positive influence on the safety of the glass curtain wall.