【摘要】 为研究风致折叠网壳结构表面积雪的分布规律,基于Euler-Euler方法和空气相与雪相单向耦合的基本假设,运用通用计算流体动力学软件ANSYS Fluent的Mixture多相流模型理论,并考虑壁面上积雪的侵蚀与沉积,建立风致雪漂的数值模型。首先,模拟立方体周围积雪分布并与实测结果对比,探讨与分析数值风洞的关键技术与参数,证实三方程k-kl-ω湍流模型能更好地对风雪两相流进行模拟。在此基础上,以风速和风向角为分析参数,模拟折叠网壳结构表面积雪分布。结果表明,10 m/s以下较低风速的持续作用对积雪分布尤为不利,受风向角变化影响,结构表面积雪的侵蚀与沉积发生在不同分区,其中迎风面被大面积侵蚀、背风面局部沉积,在不同的风向角下同一分区的积雪分布系数相对改变量最高达1.28。模拟获得结构表面在全风向角下的最不利积雪分布系数,为近似体型结构的抗风雪设计理论提供参考依据。更多还原

【Abstract】 To investigate distributions of wind-induced snow pressure on folded reticulated shell structures,a numerical simulation was conducted herein. According to the Euler-Euler method and the fundamental assumption that air and snow are one-way coupled,a numerical model was established to simulate the snow pressure around the cube firstly by Computational Fluid Dynamics( CFD) software——ANSYS Fluent. On the basis of the mixture model theory and considering the snow erosion and deposition on walls,the simulation results were obtained and compared with the measured results. Moreover,the key technology and parameters of the numerical wind tunnel are discussed. It is confirmed that the three-equation k-kl-ω turbulent model has better simulation results of air-snow two-phase flows. Based on this,regarding the wind speed and the wind direction as variable parameters,the wind-induced snow pressure on a folded reticulated shell structure was simulated. The results indicate that the sustaining action of the lower wind speed( under 10 m/s) is the worst condition,and affected by the wind direction,the snow erosion and deposition occur in different areas. The snow distribution generally shows f erosion for the windward area and local deposition on the leeward area. And the relative increase of snow distribution coefficient of the same partition under different wind direction is up to 1. 28. Through the simulation,the snow distribution coefficient was obtained,which may provide theoretical guidance for the wind and snow resistance design of similar structures.更多还原