【作者】 邓挺；

【导师】 谢壮宁； 熊光晶；

【作者基本信息】 汕头大学 ， 结构工程， 2011， 硕士

【摘要】 台风活动在我国十分频繁,随着现在全球气候变暖,气候变化越来越异常,台风的频率和强度都在增大。因此,对超高层的表面风压以及沿海一带的低矮房屋风荷载特性进行研究,对于减少我国沿海地区风灾损失以及国民经济的发展将具有十分重要意义。本文首先基于CFX软件平台,按照实际尺寸建立了天津高银117的模型,采用RNG k ?ε湍流模型对平均基底荷载和表面风压进行了数值模拟研究。并且与风洞试验进行了对比,两种吻合较好。同时,通过数值模拟的方法方便地显示了流场的信息,对风压分布进行了机理分析。需要指出的是在断面棱角很明显并且靠近迎风面的地方,流体分离明显,局部风压很大,风压梯度变化剧烈,在进行围护结构设计的时候要采取必要的措施进行防范。针对广东沿海一带一类比较典型的低矮建筑双坡房屋屋面平均风压进行了数值模拟,与风洞试验对比了对比,验证了数值模拟在低矮建筑中应用的正确性。研究了屋面上的屋脊和厝头等构筑件及其尺寸对屋面平均风压的影响,针对群体布局中最具典型代表性的两个双坡屋面并列布置之间的干扰效应进行了模拟计算和风洞实试验。结果显示:屋面边缘和屋脊地方负压较大,当加上由自重较大的混泥土制成的屋脊和厝头后,使得原来在这些地方分离的流体都转移到屋脊和厝头上,屋面负压的绝对值下降,是一种对屋面抗风有利的构建形式。屋脊的高度变化对整个屋面风压有一定的影响,不同风向角下影响情况是不同的。当风垂直于屋脊的时候影响作用最大,当风向与屋脊平行的时候,影响很小。两个低矮双坡房屋并列布置,存在明显干扰效应,各个部位的干扰效应不同,屋面最大负压干扰因子达到1.38,且干扰效应随着建筑间距的增大而减少,由数值模拟的风速场分析,可以发现并列布置干扰效应趋于消失的最大建筑间距。更多还原

【Abstract】 Typhoons hit coastal areas of our country frequently. With global warming, climate changes more and more abnormally and typhoon frequency and intensity increase. Therefore, the research on high-rise surface wind pressure and wind load character of low houses in costal area is very significant to reduce damage caused by typhoons in costal areas in the country and maintain a good momentum of growthin the national economy.Firstly,in this paper, the author uses CFX software platform to build the modal of Tianjin Gaoyin 117 according to its actual size and adopts RNG k ?εturbulence model to do numerical simulation for mean basal load and surface wind pressure. And compared with wind tunnel experiment,they agree well. At the same time, flow field information was displayed conveniently by numerical simulation, which does mechanism analysis to wind pressure distributions. It is needed to point out that there are obvious flow separation, big regional wind pressure and fierce wind pressure gradient change in edges are evident and near to the windward. Thus precautionary measures should be taken when palisade structure is designed.Secondly, the author simulates the average wind pressure of roof numerically, which aims at typical low houses with double slopes in costal area of Guangdong province. Then the author compares its numerical simulation with wind tunnel experiment and verifies that it is right to use numerical simulation in research on low houses. The paper studies how ridge and fastigium and their sizes affect the average wind pressure of roof and the author simulates the disturbed effect between two parallel roofs with two slopes numerically and does wind tunnel experiment, which are the most typical in group low buildings. The results show that the edge and ridge has great negative pressure and building ridge and fastigium made of concrete on the roof is a effective way for wind resistance of roof because the concrete has greater dead weight which results in the fluid gathering into the ridge and fastigium where the fluid separates and the absolute value of the negative pressure of the roof going down. The changing of the height of ridge effects wind pressure of the whole roof to some degree but depends on wind directions. Wind pressure of the whole roof is affected most when wind is perpendicular to ridge and it is affected least when wind is parallel to ridge. When two low houses with double slopes are built in parallel there has obvious disturbed effect and different parts have different disturbed effects. The biggest roofing negative pressure disturbance reaches 1.38 and the disturbed effect goes down with the distance broadening between the two parallel houses. Analyzing wind vector by numerical simulation, it can be found that the disturbance effect has a tendency to disappear when the two low houses are built in the biggest parallel distance.更多还原