【摘 要】
：
A theoretical analysis of velocity profiles in sediment-laden flows is presented by means of Prandtl-Kannan mixing length theorem. The study shows that the upwa
【机 构】
：
Maritime Research Center,School of Civil and Environmental Engineering
论文部分内容阅读
A theoretical analysis of velocity profiles in sediment-laden flows is presented by means of Prandtl-Kannan mixing length theorem. The study shows that the upward velocity of liquid-phase caused by settling sediment leads to the invalidity of the log-law and Rouse equation. The theoretical analysis takes into account the upward velocity and shows: 1) the mean velocity in sediment-laden flows follows the log-law, but the Karman constant reduces in the main flow region, 2)sediment concentration reduces the mixing length of fluid particles, 3) flow resistance reduces with the presence of sediment concentration, and 4) the sediment concentration profile deviates from the well know Rouse equation. The experimental data agree well with the equations derived on the basis of non-zero wall velocity. It is found that the wall-normal velocity should not be neglected for density gradient flows because it induces more than for pure water flows.
其他文献
The recovery of contaminants and useful substances from liquid wastes, the purification of production effluents and the separation of thermally instable mixture
Based on principal component analysis, this paper presents an application of faulty sensor detection and reconstruction in a batch process, polyvinylchloride (P
由于现行高管薪酬制度失灵,公司高管"天价"薪酬现象层出不穷,法律有了介入的必要."充分激励"是法律对高管薪酬进行指导的原则之一.文章就该原则的适用进行了探讨.
Forming technology of Mg alloy (AZ31B) sheets can be investigated by thermal deep drawing experiments. In the experiments,the blank holder and die contacting wi
通过症状自评量表(SCL-90)和工作内容量表中文版(C-JCQ)对个旧市242名中学教师进行调查.结果表明个旧市城区教师的工作压力大,心理健康状况令人担忧,且不同的教师群体表现也
A series of Mg2-xNdxNi(x=0.05,0.1,0.2,0.3)alloys and Mg1.95RE0.05Ni(RE= La,Ce,Pr,Nd,Y)ternary alloys were prepared by ball milling of mixted powder of Mg,Ni,RE
A gas-liquid mass transfer model based on an unsteady state film mechanism applied to a single bubble is presented. The mathematical model was solved using Lapl
Under the condition of simulated rain precipitation in the laboratory, with ElS and SEM observation, the effects of pH value of simulated rain on corrosion and
The role of Nd solid-solution and graM-boundary segregation in binary NiAI alloy was studied based on microhardness and compressive macrostrain. X-ray and Auger
Based on the advantages of the fiber Bragg grating sensing technology, this paper presents a principle of a novel smart concrete with fiber optical Bragg gratin