摘要
本文分析了宾汉流体中宾汉极限剪切力τB 对泥沙起动起阻碍作用的力学机制 ,得出均匀无粘性沙的起动拖曳力的一般表达式 .并对结果定性分析得到 :(1)存在粒径D ,对粒径小于 0 1D 的泥沙 ,起动中重力因素可忽略不计 ;对粒径大于 10D 的泥沙 ,宾汉极限剪切力因素可忽略不计 .(2 )宾汉流体中τc 随颗粒粒径D的变化关系为马鞍状曲线 .存在某个粒径Dmin,其所需τc 最小 .
Based on the mechanism of Bingham yield stress acting on sediment in Bingham fluid, a physics model for initiation of sediment is proposed and the general formula for critical shear stress of sediment is derived. It is found that a specific particle diameter is existed. The effect of gravity can be ignored if the diameter of sediment is smaller than the specific diameter; otherwise, the effect of Bingham yield stress can not be ignored. It also found that there exits a certain diameter for which the yield stress will be minimum.
出处
《水利学报》
EI
CSCD
北大核心
2000年第12期64-67,共4页
Journal of Hydraulic Engineering
基金
国家自然科学基金重点项目!(498310 10 )
国家教委"跨世纪优秀人材计划"基金资助
