粗糙壁面高层建筑风荷载的CFD模拟

发布时间：2018-02-09 07:43

本文关键词： 粗糙壁面钝体绕流 CFD模拟风洞试验　出处：《西南交通大学》2017年硕士论文　论文类型：学位论文

【摘要】：高层建筑需要考虑风荷载作用,国内外对高层建筑风荷载的研究对象主要为外形规则的建筑,对表面带有装饰条或因建筑造型需要而导致壁面粗糙的高层建筑结构的风荷载特性研究较少。现代建筑为了功能以及审美需求,往往表面做成凹凸起伏等复杂形状,导致风荷载特性的差别较大,因此有必要对高层建筑风荷载研究中存在的粗糙壁面情况展开分析与讨论。本文具体工作和结论如下:(1)在概述风工程数值模拟的基本理论基础上,介绍了高层建筑数值模拟的标准模型CAARC模型,探讨了数值模拟基本参数的选取和设置。主要对网格独立性进行了验证。(2)进行二维数值风洞模拟,着重对比了截面长宽比、壁面凸起的高度和间距等参数对气动力、风压分布和流场的影响。(3)选取一实际建筑进行三维数值模拟,对比风洞试验结果。初步探讨粗糙壁面高层建筑的风荷载特性。(4)计算结果表明,本文采用的结构当来流方向正对迎风面时,迎风面上的凹凸会对风起到汇聚作用,使其风压系数增大;在侧面凹凸区内会形成较小的漩涡,在凹凸区外气流加速,流速梯度加大,风压系数略微减小;在背风面,粗糙的壁面产生的漩涡范围较大,且回流速度小于光滑壁面相应的速度,风压系数绝对值表现为减小。
[Abstract]:High-rise buildings need to consider the action of wind load. The research object of wind load of high-rise buildings at home and abroad is the building with regular shape. There are few studies on wind load characteristics of high-rise building structures with decorative strips or rough walls caused by architectural modeling. For the purpose of function and aesthetic demand, modern buildings often make complex shapes such as ups and downs. So it is necessary to analyze and discuss the rough wall in the wind load research of high-rise building. The concrete work and conclusion are as follows: 1) based on the basic theory of wind engineering numerical simulation, The standard model CAARC model for numerical simulation of high-rise buildings is introduced, and the selection and setting of basic parameters of numerical simulation are discussed. The influence of the height and spacing of the wall bulge on aerodynamic force, wind pressure distribution and flow field. Comparing with the results of wind tunnel test, the calculation results of wind load characteristics of tall buildings with rough walls show that when the direction of the incoming current is positive to the upwind surface, the concave and convex on the upwind surface will converge on the wind. The wind pressure coefficient is increased, a smaller swirl is formed in the lateral concave and convex region, the velocity gradient increases and the wind pressure coefficient decreases slightly outside the concave and convex zone, and on the leeward surface, the swirl range of the rough wall surface is larger. The reflux velocity is smaller than that of smooth wall, and the absolute value of wind pressure coefficient decreases.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU973.213

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