%0 Journal Article
%T Mechanisms of particle vertical diffusion in sediment-laden flows<br>Mechanisms of particle vertical diffusion insediment-laden flows
%A WANG Guangqian
%A FU Xudong Key Lab for Water
%A Sediment Sciences of Ministry of Education
%A Tsinghua University
%A Beijing
%A China Correspondence should be addressed to Wang Guanqian
%A <br>WANGGuangqian
%A FUXudong
%J 科学通报(英文版)
%D 2004
%I 
%X Diffusion coefficient of natural sediments and effects of lift force and gradient in particle velocity fluctuations were investigated through using a closed kinetic model. Comparison against experimental data of Einstein & Chien (1955) validated the model. The diffusion coefficient eyy of medium and large sediments distinctly exceeds fluid eddy viscosity n tf, while eyy of fine sediments approximately equals n tf. In the measured region of 0.03<y/H<0.4, eyy /n tf increases with the distance from the wall decreasing. Combined effects of lift force and gradient in particle velocity fluctuations change sediment gravitational settling remarkably below y/H=0.2, and need to be accounted for describing sediment diffusion in this region.
%K sediment
%K two-phase flows
%K kinetic model
%K diffusion coefficicnt
%K lift force<br>沉积物
%K 两相流
%K 动力模型
%K 扩散效率
%K 升力
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=01BA20E8BA813E1908F3698710BBFEFEE816345F465FEBA5&cid=96E6E851B5104576C2DD9FC1FBCB69EF&jid=DD6615BC9D2CFCE0B6F945E8D5314523&aid=8D35A43CCD7386F5F21F515D895D5ADF&yid=D0E58B75BFD8E51C&vid=2A3781E88AB1776F&iid=F3090AE9B60B7ED1&sid=3395C64999261B75&eid=602F518C16859E7D&journal_id=1001-6538&journal_name=科学通报(英文版)&referenced_num=0&reference_num=22