平屋面摩擦速度的数值模拟研究  

NUMERICAL SIMULATION OF FRICTION VELOCITY OF FLAT ROOFS

作　　者：辛林桂 周晅毅[1] 顾明[1] XIN Lin-gui;ZHOU Xuan-yi;GU Ming(State Key Laboratory of Disaster Reduction in Civil Engineering,Tongji University,Shanghai 200092,China)

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：《工程力学》2024年第2期151-159,共9页Engineering Mechanics

基　　金：国家自然科学基金项目(52078380);科技部国家重点实验室基金项目(SLDRCE19-B-14)。

摘　　要：建筑屋面的摩擦速度是决定其风致迁移雪荷载的重要因素。该文采用CFD(computational fluid dynamics)方法模拟了平屋面的摩擦速度,并结合其分布特征分析了屋面积雪传输率、侵蚀通量和暴露系数随跨度的变化趋势。为验证CFD方法的湍流模型对平屋面摩擦速度模拟的影响,将数值模拟结果与Irwin探头风洞试验进行了对比,结果表明Realizable k-ε湍流模型的模拟结果与风洞试验最为接近。根据4种不同跨度屋面的CFD模拟结果发现,当屋面跨度与高度之比为4时,屋面平均摩擦速度最小;并且随着跨度的增大,屋面摩擦速度最小值所在的位置和积雪沉积的区域均逐渐向迎风侧屋檐靠近。同时发现,屋面积雪的平均侵蚀通量随着跨度的增大而减小,屋面积雪传输率和雪荷载暴露系数则随着跨度的增大而增大。The friction velocity of building roof is an important factor to determine the drifted snow load.In this paper,CFD(computational fluid dynamics)method is used to simulate the friction velocity of the flat roof.In addition,combined with its distribution characteristics,the variation trends of snow transport rate,snow erosion flux,and exposure factor with span are analyzed.To verify the effect of the turbulence model simulated by CFD on the friction velocity of the flat roof,the numerical simulation results are compared with the Irwin probe wind tunnel test.The results show that the simulation results of the Realizable k-εturbulence model are most close to the friction velocity results obtained from the wind tunnel test.According to the CFD simulation results of four roofs with different spans,when the ratio of roof span to height is 4,the mean friction velocity of the roof is the smallest.And with the increase of roof span,the position of the minimum roof friction velocity and the area of snow deposition are both gradually closer to the windward eaves.Meanwhile,it is found that the mean snow erosion flux of the roof decreases with the increase of the roof span,while the snow transport rate and snow load exposure factor increase with the increase of the roof span.

关 键 词：计算流体动力学(CFD) 平屋面 Irwin探头 摩擦速度 积雪传输率 

分 类 号：TU973.213[建筑科学—结构工程]