平坦床面上风雪流运动的力学机理分析

	平坦床面上风雪流运动的力学机理分析
Alternative Title	Analysis of mechanism for snow drift above a flat particle bed
	张洁
Thesis Advisor	黄宁
	2008-06-05
Degree Grantor	兰州大学
Place of Conferral	兰州
Degree Name	硕士
Keyword	风雪流内聚力临界风速随机运动耦合作用
Abstract	根据床面雪粒粘连程度的不同，建立不同的起动模型，并讨论温度在零下30度到零度的范围内，起动风速与粒径、温度以及积雪时间的关系。建立单颗雪粒的运动模型，分别讨论了在不同情况下各种因素对雪粒运动轨迹的影响。结果表明：除重力和拖曳力外，saffman力、magnus力、静电力以及运动随机性对雪粒的运动也有重要的影响，并且随着风速、雪粒粒径、密度的变化各因素的影响程度也发生不同程度的变化。基于对雪粒起动、运动机理的分析，结合初速度分布函数，建立稳态的风雪流计算模型，并对稳定状态下的风雪流结构进行分析，将分析的结果与风洞试验的测量值进行了比较。通过击溅函数模拟了风雪流的发展过程，讨论了不同风速下风雪流发展时间的变化以及发展稳定后的单宽输雪率。
Other Abstract	According to the adhesion degree of snow grains on the bed, this paper have established different initiation models and respectively analyzed the relationship between threshold wind velocity and particle size, temperature and snow cover time. Established a movement model of single snow particle and discussed the influence of various factors on motion trajectory of snow particle at different situations. The results show that besides the gravity and the drag force, the saffman force, the magnus force, the electric field force as well as motion randomicity also have important influence to a snow grain movement, which changes with different wind speed, particle size and particle density. A computation model of the evolution process of wind-snow drift has been established, combined with initial velocity distribution function. We analyze the structure of the snow drift and compare it with the value of cold wind tunnel test. On the basis of splash function, we simulated the evolution of snow drift and calculated the time for the entire system to reach a steady state of snow drift and the snow flux in steady state.
URL	查看原文
Language	中文
Document Type	学位论文
Identifier	https://ir.lzu.edu.cn/handle/262010/226045
Collection	土木工程与力学学院
Recommended Citation GB/T 7714	张洁. 平坦床面上风雪流运动的力学机理分析[D]. 兰州. 兰州大学,2008.

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