大跨度屋盖表面风致雪压分布规律研究  

Study on wind-induced snow pressure on large-span roof

作　　者：周晅毅[1] 顾明[1] 李雪峰[1] 

机构地区：[1]同济大学土木工程防灾国家重点实验室,上海200092

出　　处：《建筑结构学报》2008年第2期7-12,共6页Journal of Building Structures

基　　金：国家自然科学基金(50608060);国家自然科学基金创新研究群体科学基金(50621062);同济大学青年优秀人才培养行动计划联合资助

摘　　要：采用了两相流理论模拟风荷载雪漂作用,认为空气相和雪相的关系为单向耦合,雪在风(空气相)的作用下发生漂移,基于此对通用流体软件FLUENT进行了二次开发。以一实际大跨屋盖结构——北京首都机场3号航站楼T3A为研究对象,首先将风洞试验测得的屋盖表面风压分布数据与计算流体动力学(computational fluid dynamics)计算结果进行了对比,两者的一致性一定程度上证实了风致雪漂计算方法的准确性。接着细致分析了几个主要参数(湍流模型的类型、阀值摩擦速度及来流风速、风向等)对屋盖表面雪压变化的影响。结果表明,相对标准k-ε模型而言,可实现k-ε模型得到的结果有更多的沉积区域;随着阀值摩擦速度的提高或来流风速的降低,沉积率相应增大。Drifting snow in wind is considered in this paper as a two-phase flow problem. The mixture of air and snow is assumed to be one-way coupled so that the air phase can be treated as unaffected by the airborne snow, and the snow transport is mainly controlled by the air flow and surface conditions. The commercial CFD software, FLUENT, is adopted, with additional use of C ＋ ＋ code added to model the accumulation or erosion of snow. The mean wind pressures on the Terminal 3A of Beijing International Airport obtained from the wind tunnel test and numerical method are first compared to verify the reliability of computational fluid dynamics （CFD） results to some extent. Then the effects of some major parameters including the type of turbulence model, threshold of friction velocity, magnitude of wind velocity and wind directions, on the snow drift are analyzed. It is found that snow accumulation ratios obtained by using the realizable k-ε model are somewhat larger than those obtained by using the standard k-ε model, and snow accumulation ratio increases as threshold velocity increases or wind velocity decreases.

关 键 词：大跨度屋盖结构 风洞试验 计算流体力学(CFD) 两相流 雪漂 

分 类 号：TU393.3[建筑科学—结构工程] TU312.1