利用颗粒图像测速仪对新雪形成的风吹雪进行风洞实验研究,给出了不同高度处雪粒粒径分布函数以及平均粒径廓线、雪粒数通量廓线的分布规律.发现当摩阻风速大于0.5m/s时单宽输雪率与摩阻风速满足指数函数的关系,小于0.5m/s时两者满足幂函数的关系,总体而言,单宽输雪率与摩阻风速呈线性关系.
In previous wind tunnel experiments on drifting snow, the artificial or compacted snow is usually usedas a substitute for the natural snow. But there is a big difference between the natural snow and its substitutes in their physical and mechanical properties. In this paper, the movement of the fresh snow is studied by the particle image velocimetry, including the distributions of the snow size with the height, and the vertical profile of the mean particle size and the snow particle numbe~ flux. The results show that the snow transport rate can be expressed as an exponential function at the high friction velocity (u. 〉 0.5 m/s), and a power function at the low friction velocity (u. 〈 0.5 m/s). In overall, the transport rate linearly increases with the friction velocity.