局部开洞的轻型四坡折叠房屋表面风压分布研究

发布时间：2018-11-10 20:35

【摘要】：折叠帐篷在野营、抢险救灾和临时住房中越来越受到青睐,它具有材质轻、风敏感性强等特点,为了采光、通风和人流进出的需要,对建筑表面的开洞是必不可少的。房屋开洞后对外部风压来说,则打开了内部气体的空间,建筑表面不再只单受外部风压的影响,而是有内外风压共同作用,建筑物内外部空气压力的影响对于建筑主结构的设计尤为重要,四坡攒尖房屋在墙面开洞和屋面开洞下的风压分布在国内外规范中尚无参考依据,故本研究内容为类似建筑的抗风设计提供了一定的理论依据和工程价值。为研究局部开洞下轻型四坡攒尖房屋的内外表面风压分布、流场特性以及室内舒适度,本文基于计算流体动力学和大气边界层的基本原理,采用FLUENT软件对TTU的足尺风洞试验模型进行了数值模拟,并与TTU现场实测数据进行对比,探讨分析了湍流模型、网格划分、速度压力耦合算法等参数的选取对开洞建筑数值模拟的可靠性;在此基础上,研究了单双墙面开洞和屋面开洞随来流风向、开洞大小和开洞位置变化的内外表面风压分布规律,并探讨与分析了单双墙面开洞和屋面开洞对四坡折叠房屋体型系数和室内舒适度的影响。研究结果表明:开洞面积的增大和开洞位置的升高对屋顶面屋脊和攒尖尖顶处的负压峰值系数影响较大;单墙面开洞下内压系数与理论公式计算值较为接近,洞口位于迎风面时,内压系数急剧增大,房屋被“掀起”的概率较高,洞口与来流风向平行时,内压表现为吸力,房屋被“吹垮”的可能最大;双墙面开洞下可有效降低房屋被“掀起”的可能,其内压系数可参照国际标准ISO4354、澳大利亚或英国的荷载规范进行取值;屋面开洞具有提高两侧较低风速和降低中部偏高风速的效果,尤其对双墙面开洞下作用更加明显。
[Abstract]:Folding tent is more and more popular in camping, emergency rescue and temporary housing. It has the characteristics of light material and strong wind sensitivity. In order to meet the needs of lighting, ventilation and people flow in and out, it is necessary for the opening of the building surface. After the opening of a building, for the external wind pressure, it opens the space of the internal gas. The building surface is no longer only affected by the external wind pressure, but also by the internal and external wind pressure. The influence of air pressure inside and outside the building is particularly important for the design of the main structure of the building. There is no reference basis for the distribution of the wind pressure under the wall opening and roof opening in the Sipo Zanjian building in the domestic and foreign codes. Therefore, this study provides a certain theoretical basis and engineering value for the wind resistant design of similar buildings. In order to study the wind pressure distribution, the flow field characteristics and the indoor comfort of the light Sipo Shaojian building under the local opening, this paper is based on the basic principles of computational fluid dynamics and atmospheric boundary layer. The full-scale wind tunnel test model of TTU is simulated by FLUENT software, and compared with the field measured data of TTU, the turbulence model and mesh division are discussed and analyzed. The reliability of numerical simulation of open-hole building is obtained by selecting parameters such as velocity and pressure coupling algorithm. On this basis, the distribution of wind pressure on the inside and outside surfaces of single and double wall openings and roofing holes with the wind direction, the size and the location of the holes are studied. The effects of single and double wall opening and roof opening on the shape coefficient and indoor comfort of four slope folding houses are discussed and analyzed. The results show that the increase of the opening area and the location of the hole have a great influence on the peak negative pressure coefficient of roof and the top of the roof. The internal pressure coefficient under the single wall opening is close to the calculated value of the theoretical formula. When the hole is located on the upwind side, the internal pressure coefficient increases sharply, and the probability of the house being "lifted" is higher. When the orifice is parallel to the incoming wind, the internal pressure is shown as suction. Houses are most likely to be blown down; Under the double wall opening can effectively reduce the possibility of the house being "lifted", its internal pressure coefficient can refer to the international standard ISO4354, load code of Australia or the United Kingdom to get the value; The roof opening has the effect of increasing the low wind speed on both sides and reducing the high wind speed in the middle, especially for the double wall opening.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU312.1

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