【作者】 吕军；

【导师】 楼文娟；

【作者基本信息】 浙江大学 ， 结构工程， 2008， 硕士

【摘要】 通风双幕墙具有良好的通风性能和采光性能,极大的改善了建筑的舒适度并且节约能源。近年来随着人们对建筑舒适度和绿色环保的重视,双幕墙的应用日渐增多。由于外层幕墙设有一定的开孔率,外表面风压通过孔口影响到廊道内的风压分布,使双幕墙风荷载变得较为复杂,抗风设计时不能简单的套用单幕墙建筑的风压。研究双幕墙的风压分布特征是十分必要的。本文采用数值模拟(CFD)的方法研究了圆柱形高层建筑双层幕墙的平均风荷载特性。分析全圆柱设置双幕墙的高层建筑平均风荷载。固定廊道的高度,通过变化廊道间距和外幕墙的开孔率建立了16个模型。研究了圆柱形双幕墙的流场特性和风压分布特性,探讨了廊道间距和外幕墙开孔率对圆柱形双幕墙风压分布的影响,着重分析了建筑外部绕流受孔口流出气流的干扰效应。并在廊道内设置粗糙元以模拟廊道内通常存在的卷帘或百叶等遮阳设施的实际情况,研究粗糙元对双幕墙风压分布的影响。分析半圆周布置双幕墙的圆柱形高层建筑平均风荷载。建立了一个半圆周布置双幕墙另一半为单幕墙的圆柱形双幕墙的截断模型,分析了不同风攻角下该模型的风压和风场特性。研究发现这种局部布置双幕墙的圆柱形高层建筑由于不具有对称性,其风荷载更为复杂。在某些风攻角下,不但阻力大幅增大,而且还会产生比较大的横风向升力,值得引起重视。更多还原

【Abstract】 For the double-skin facades have good ventilation performance and lighting performance, they improve greatly the comfort of buildings and can also save energy. The double-skin facades are applied gradually to buildings as people pay more attention to the comfort of buildings and the protection of environment. Due to the opening ratio of the external skin facades, the external pressure influenced the pressure in the gap of double-skin facades through the openings, which complicates the wind loads acting on double-skin facades and makes wind-resistance design of double-skin facades different with the single-skin facades. It is necessary to study the characteristics of the pressure distribution on double-skin facades extremely. This article adopts numerical simulation method to study the characteristics of average wind loads on high cylindrical building with double-skin facades.The average wind loads acting on double-skin facades setting on all directions of cylindrical building were analyzed. Sixteen models, which have fixed gap height, four types of gap width and four kinds of porosity, were created. The characteristics of flow filed and the wind pressure distribution on cylindrical buildings with double-skin facades were studied. The influence to the pressure distribution on cylindrical buildings with double-skin facades in light of the opening ratio of the external skin facades and gap width was discussed. It was studied that the external flow around the building was influenced by the outflow air from the gap. In order to study the influence on the pressure distribution on double-skin facades due to roughness, roughness setting in the gap to simulate the actual equipment such as shutter was considered.The average wind loads acting on double-skin facades setting on half circle of high cylindrical buildings were considered. The wind loads and flow field characteristics acting on double-skin facades under seven different wind directions were considered by establishing a part of cylindrical building with double-skin facades and single-skin facades. It was indicated that wind loads on this type of double-skin facades were more complicated. There was a large lift force on the building under some wind directions except the increase of the drag force.更多还原