Viscosity and heat transfer in fluidized snow
Viscosity and heat transfer in fluidized snow
复制标题
流化雪中的粘度和传热
DOI：
10.3189/s0022143000010807
复制
发表时间：
1980
影响因子：
3.4
通讯作者：
Y. Kaneda
中科院分区：
文献类型：
--
作者：
N. Maeno;K. Nishimura;Y. Kaneda
摘要在冷态实验室中制备了流态化雪，并对其粘度和传热特性进行了研究。使用改进的Stormer型粘度计测量液化雪的粘度。结果表明，随着空气流速的增加和颗粒直径的减小，表观粘度降低。根据粘度与空气速度倒数的关系曲线，提出了产生流化雪粘度的两种机制。传热系数通过测量悬浮在流化雪中的冷却黄铜球的温度来获得。流化雪的传热系数是不含雪颗粒的空气流的三到四倍。增加是由于增强湍流的气流和雪颗粒的碰撞;后者的贡献估计是80至90%的总增加，由于雪的流化。这些结果也证实了在一个寒冷的水平风洞中产生的人工吹雪通过测量传热系数，风速和漂移密度。
Abstract Fluidized snow was produced in a cold laboratory and its viscosity and heat transfer were studied. The viscosity of the fluidized snow was measured with a modified Stormer-type viscometer. It was found that the apparent viscosity decreased with increasing air velocity and decreasing particle diameter. Two mechanisms were suggested as producing the viscosity of the fluidized snow on the basis of the plot of the viscosity against the reciprocal of the air velocity. The heat-transfer coefficient was obtained by measuring the temperature of a cooled brass sphere suspended in the fluidized snow. The heat-transfer coefficient in the fluidized snow was three or four times larger than that in an air flow containing no snow particles. The increase was attributed to the enhanced turbulence of air flow and the collision of snow particles; the contribution of the latter was estimated to be 80 to 90% of the total increase due to the fluidization of snow. These results were also confirmed in an artificial blowing snow produced in a cold horizontal wind-tunnel by measuring the heat-transfer coefficient, wind velocity, and drift density.