落地四坡房屋表面风致雪漂移效应分析

CFD simulation of snow drifting on folding landing hipped camping house

为了获得落地四坡房屋表面积雪分布规律,根据风雪运动机理选取适当的雪粒粒径、积雪密度、沉降速度等条件,考虑积雪侵蚀沉积等影响因素,基于Euler-Euler多相流理论,使用FLUENT软件Mixture多相流模型模拟了立方体周围积雪及高低屋盖模型表面积雪分布,并与实测进行了比较,确定了湍流物理方程、数值风洞尺寸、细部网格及数量、壁面条件等各计算参数设置。以风速、风向角为参数,模拟落地四坡房屋屋面积雪分布得出:随着风速增加,屋面积雪量不断减少,15m/s风速下屋面积雪呈完全侵蚀状态,低风速下屋面积雪更多;屋面各区域积雪漂移随着风向角的改变不断改变,总体表现为侵蚀状态沉积区域较少;在5m/s风速下落地四坡房屋的迎风面各区域积雪分布系数在0.5以下,迎风屋顶各区域积雪分布系数基本为0,背风屋顶各区域积雪分布系数变化幅度高达0.8,背风面各区域积雪分布系数整体保持在0.9附近。得到了5m/s风速下区域积雪分布系数表,可为该类房屋的设计使用提供理论依据。

To study the snow drifting on folding landing hipped camping house, numerical investigations using Fluent based on the Euler-Euler method and the mixture model theory considering the particle size, density, settling speed, the erosion and deposition is conducted. The turbulent flow model, computational domain and the mesh size used in the numerical simulation are determined according to the simulation of the snow around a cube and the snow distribution on a stepped flat roof. Regarding the wind direction and speed as variable parameters, the snow drifting on folding landing hipped camping house is simulated. Results obtained indicate that the smaller wind speed has a greater impact on the roof snow and the snow erosion and deposition distribute at different areas affected by the wind direction. Under 5 m/s wind speed, the snow distribution coefficient of windward area is below 0.5, the snow distribution coefficient of windward roof is basically 0, the variation of the snow distribution coefficient on leeward roof is 0.8 and the snow distribution coefficient of leeward area is close to 0.9. The snowdistribution coefficient is obtained, which may provide theoretical reference for the snow resistance design of similar structures.