偏斜风对地物周边空间吹雪及积雪形成的影响

为考察偏斜风效应下地面结构周边地表积雪形态及形成机理，基于欧拉框架多相流理论，采用计算流体动力学（CFD）方法，模拟了不同来流风向下立方体建筑的特征绕流场，对比了地表侵蚀积雪预测指标的差异.研究结果表明:来流风向的改变影响模型周边近地流分离及附着的形成，决定了地表剪切状态，顺风体轴方向，风向角的增大（045）使侵蚀极值位置总体后移，模型背风侧极值位置随风向的改变较迎风侧敏感；空间吹雪浓度分布受模型特征扰流及风向重分配效应影响显著，决定了当地沉积强度，横风体轴方向，靠近来流侧近地吹雪浓度始终大于出流侧，两侧浓度差随风向角的增大（045）而增大.单位时间下地物水平正交方向的侵蚀沉积量随风向的改变呈现此消彼长的规律，风向对局部地表积雪形态的调整机制近似动态平衡. 

Influence of Skew Wind on Snow Drifting and Snow Deposition Around a Ground Object

To clarify the mechanism of snow drifting and snow deposition caused by skew wind around the ground building, using CFD (Computational Fluid Dynamics) method, the characteristic ambient flows around a cubic building under different wind directions were simulated and indicators for erosion and deposition in the prediction model were compared. The results indicate that wind directions () affect the boundary-layer separation and reattachment and determine the shear state of ground surface. In the x body-axis direction, extreme erosion positions move backward generally with the increasing of (045), and the changes of the extreme positions at the leeward side are more sensitive to than those at the windward side. The distributions of drifting snow densities are significantly influenced by the feature ambient flows and the redistribution effect caused by skew wind, which determine the surface deposition. In the y body-axis direction, the drifting snow densities near the ground at the inlet side are always larger than the one at the outlet side, and the concentration difference increases with (045). The increase of snow erosion and deposition rate in one direction leads to decrease in its orthogonal direction, and the skew wind can flexibly adjust the local snow coverage to quasi-dynamic equilibrium.