平面局部凸出的双坡房屋表面风压特性分析及体型优化研究∗

以计算流体动力学和大气边界层基本理论为依据,对平面局部凸出的双坡野营房屋表面风压分布特性展开研究,在此基础上对其建筑外形进行合理的优化。研究过程中运用Fluent软件对模型进行分析和计算,并将数值模拟与TTU实测的结果进行对比,进而确定数值风洞的相关参数。将我国野营房屋使用的功能要求以及人体活动所需的空间尺度等作为依据,在此基础上建立模型,并在风向角、辅助建筑相对尺寸和建筑平面布置形式等的变化下,计算分析房屋表面的风压分布规律,最后将结果归纳为房屋的风荷载体型系数,以便抗风设计使用。进一步将房屋表面风压的平均值、极值和标准差作为优化目标,对平面局部凸出的双坡野营房屋的体型进行优化,最终得到该类型房屋风作用最小的合理建筑外形,以提高其抗风性能。结果表明:轻型双坡野营房屋因自身凸出的辅助建筑的存在,建筑周围的气流运动会受到影响,从而使建筑表面风压分布规律发生变化,更会出现主体建筑局部风荷载体型系数发生变号的现象,鉴于以上情况,可知辅助建筑对建筑表面风压的影响在抗风设计中必须予以重视。

Study on the Wind Pressure Distribution Characteristics and Shape Optimization of Gable Roof House with Partially Protruding Plane

Based on the basic theories of computational fluid dynamics and atmospheric boundary layer, the wind pressure distribution characteristics of the double-slope camping houses with local convexity are studied. On this basis, the structural shape of the building is rationally optimized. During the research, Fluent software was used to analyze and calculate the model, and the numerical simulation was compared with the results of TTU measurement to determine the relevant parameters of the numerical wind tunnel. The models are built based on the functional requirements of the use of camping houses in China and the spatial scale required for human activities. The wind pressure distribution on the house surface is calculated and analyzed considering the changes of wind direction angle, relative size of auxiliary buildings and layout of buildings. The wind pressure distribution law is finally summarized as the wind load shape coefficient of the house, so that it can be used in wind resistance design. Furthermore, the average value, extreme value and standard deviation of the wind pressure on the house surface are used as the optimization targets, and the shape of the double-slope camping house with partial convexity is optimized. Finally the reasonable building shape of each house type with the least wind effect is obtained to improve wind resistance. The analysis results show that due to the existence of auxiliary structures protruding from the double-slope camping houses, the air movement around the building will be affected, so that the wind pressure distribution law of the building surface changes, and even more, reversal of the wind load shape coefficient of the main building will appear. In view of the above situation, it can be seen that the influence of the auxiliary building on the wind pressure of the building surface must be taken into account in the wind resistance design.