摘要
本文在对风沙流进行气固两相流分析的基础上实现了低风速条件下的沙粒起动过程,借助PⅣ测量系统对其进行了观测并对影响因素进行了分析,获得了沙粒的浓度和速度分布。实验结果表明沙粒浓度沿距离沙面的高度呈负指数分布特征。流体起动和冲击起动下的输沙率随摩阻速度和雷诺数的增加而单调增加,而起动效能比随之减小并趋向于常数0.207。测量得到的输沙率修正了低速范围内的Bagnold公式和河村龙马公式。
In this paper, on the basis of the analysis of the characteristics of wind-blown-sand flow in view of gas-solid two-phase flow, the sand incipience process was realized and observed by using Particle Imaging Velocimeter （PIV） technique in a specially designed test facility and the influence factors were discussed. By treating PIV images profiles of sand concentration and＇velocity were obtained. It has been found that the sand concentration shows a negative exponential profile along the height over the sand surface. The sand transport, rates of the fluent incipience and the impact incipience increase monotonically with increased friction velocity and flow Reynolds number, while the ratio of incipient efficiency decreases and tends to a constant of 0.207. The measured sand transport rate has modified the Bagnold and Kawamura formulae in the low velocity range.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2005年第5期805-807,共3页
Journal of Engineering Thermophysics
基金
清华大学基础研究基金"沙漠迁移过程中的气固两相流动规律"项目资助
关键词
沙粒起动
输沙率
起动做能比
PIV
sand incipience
sand transport rate
ratio of incipient efficiency
PIV
