不同平移速度龙卷风对高层双坡屋面的作用研究

发布时间：2018-04-09 23:41

本文选题：平移速度　切入点：龙卷风　出处：《建筑结构学报》2015年01期

【摘要】：采用计算流体动力学计算方法,对不同平移速度的龙卷风作用下典型高层双坡屋面的风荷载进行了数值研究。综合滑移网格和动网格的各自优势,利用动网格法和滑移交界面分割技术,实现了等效移动龙卷风场的数值模拟。计算研究表明:龙卷风场作用下,各种坡角(0°、15°、30°和60°)的计算模型的屋面风荷载均为吸力,在距风场中心距离为最大切向风速所对应半径的附近,屋面吸力最大;在等效移动龙卷风场中,由于充分捕捉了龙卷风场作用于计算模型过程中的动态效应,屋面的吸力远大于其在静止龙卷风场中的吸力,30°坡角屋面吸力增幅最大(83.9%),0°坡角屋面吸力增幅最小(74.3%);在距风场中心距离为最大切向风速所对应半径的附近,出现了风压激增区,在此区域屋面的吸力急剧增大,等效移动龙卷风场中此现象更加明显。此外,龙卷风的风致破坏不仅与其风场强度正相关,而且与平移速度也大致呈正相关,计算模型屋面风压随平移速度的增大而增大,但当平移速度超过某限值(约为最大切向风速的25%),计算模型屋面风压略有下降。
[Abstract]:A numerical study of wind loads on a typical high-rise double-slope roof under the action of tornadoes with different translational velocities was carried out by using computational fluid dynamics (CFD) method.Based on the advantages of sliding mesh and moving grid, the numerical simulation of equivalent moving tornado field is realized by using dynamic grid method and sliding interface segmentation technique.The calculated results show that under the action of tornado field, the roof wind loads of various slope angles of 0 掳/ 15 掳/ 30 掳and 60 掳) are all suction, and the maximum suction is near the radius corresponding to the maximum tangential wind speed at the distance from the center of the wind field.In the equivalent moving tornado field, the dynamic effect of tornado field acting on the calculation model is fully captured.The suction of the roof is much larger than that of the roof at the angle of 30 掳slope in the static tornado field. The maximum increase in the suction of the roof is 83.9 掳/ 0 掳and the minimum increase is 74.3%, and a surge area of wind pressure appears near the distance from the center of the wind field to the radius corresponding to the maximum tangential wind speed.In this area, the suction of roof increases rapidly, and this phenomenon is more obvious in the equivalent moving tornado field.In addition, the wind damage caused by tornadoes is positively correlated not only with the wind field intensity, but also with the translational velocity. The calculated roof wind pressure increases with the increase of the translational velocity.However, when the translation velocity exceeds a certain limit (about 25% of the maximum tangential wind speed), the calculated roof wind pressure decreases slightly.
【作者单位】：东南大学土木工程学院;郑州大学力学与工程科学学院;
【分类号】：TU352.2

【相似文献】