攒尖四坡屋面风致雪漂移的数值模拟

Numerical simulation of snow drifting on pyramidal hipped roof

为获得攒尖四坡屋面的风致雪漂移规律,基于欧拉-欧拉方法和风雪单向耦合假定,运用计算流体动力学软件,选取Mixture模型分别对立方体周边和高低屋面上的风致雪漂移运动进行数值模拟,将模拟结果与两者的实地观测数据对比,探讨分析数值风洞的关键技术和参数设置,验证数值模拟方法的合理性与可靠性。依据攒尖四坡房屋的使用功能要求,设计分析模型与分析工况,在试算的基础上对屋面进行分区。以风速5 m/s,7 m/s,9 m/s,11 m/s,13 m/s和15 m/s,风向角0°,15°,30°和45°以及屋面坡度25°,30°,34°,40°和45°为分析参数,对攒尖四坡房屋的120种工况进行数值模拟,得到屋面各分区侵蚀沉积的基本规律,提出可用于抗雪设计的屋面积雪分布系数。研究表明,风向角的改变会使屋面积雪分布状态发生较大程度的变化,风速和屋面坡度的变化对屋面整体积雪量有较大影响。

Numerical simulation was conducted to research snow drifting on pyramidal hipped roof based on Euler-Euler method and one-way coupling assumption of wind and snow,using computational fluid dynamics software.The Mixture model was selected to simulate snow drifting around a cube and on a stepped flat roof.Reliability and reasonability of the numerical simulation method was verified by comparing simulation results with observed datas,and key techniques and parameters of a numerical wind tunnel were discussed and analyzed and discussed.The analysis models and cases were designed according to functional requirements of a pyramidal hipped house.The partition of roof was determined on the basis of trial calculation.Regarding wind speed at 5 m/s,7 m/s,9 m/s,11 m/s,13 m/s,15 m/s,wind direction 0°,15°,30°,45°,and roof slope 25°,30°,34°,40°,45°as variable parameters,through numerical simulation of 120 working conditions for a pyramidal hipped house,the basic law of erosion and deposition on roof is obtained,and snow distribution factor which can be used for snow resistance design is put forward.The results show that the change of wind direction angle will lead to a great change in the snow distribution on the roof,and changes in wind speed and roof slope have a great impact on the overall snow cover.