Vertical disoersion of fine and coarse sediments in turbulent open-channel flows | |
Fu, XD ; Wang, GQ ; Shao, XJ | |
2010-05-11 ; 2010-05-11 ; OCT | |
关键词 | RAPID GRANULAR FLOWS PARTICLE DEPOSITION SUSPENDED SEDIMENT KINETIC-THEORY PIPE-FLOW HEAT-TRANSFER 2-PHASE FLOW SHEAR FLOWS LADEN FLOW TRANSPORT Engineering, Civil Engineering, Mechanical Water Resources |
中文摘要 | Through using a kinetic model for particles in turbulent solid-liquid flows, underlying mechanisms of sediment vertical dispersion as well as sediment diffusion coefficient are investigated. Four hydrodynamic mechanisms, namely gravitational settling, turbulent diffusion, effect of lift force, and that of sediment stress gradient, coexist in two-dimensional (2D) uniform and steady open-channel flows. The sediment diffusion coefficient consists of two independent components: one accounts for the advective transport of sediment probability density distribution function due to sediment velocity fluctuations, and the other results from sediment-eddy interactions. Predictions of the kinetic model are in good agreement with experimental data of 2D open-channel flows. In such flows, it is shown that: (1) the parameter gamma (i.e., the inverse of the turbulent Schmidt number) may be greater than unity and increases toward the bed, being close to unity for fine sediments and considerably large for coarse ones; (2) effects of lift force and sediment stress gradient become significant and need to be considered below the 0.1 flow depth; and (3) large errors may arise from the traditional advection-diffusion equation when it is applied to flows with coarse sediments and/or high concentrations. |
语种 | 英语 ; 英语 |
出版者 | ASCE-AMER SOC CIVIL ENGINEERS ; RESTON ; 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA |
内容类型 | 期刊论文 |
源URL | [http://hdl.handle.net/123456789/27440] ![]() |
专题 | 清华大学 |
推荐引用方式 GB/T 7714 | Fu, XD,Wang, GQ,Shao, XJ. Vertical disoersion of fine and coarse sediments in turbulent open-channel flows[J],2010, 2010, OCT. |
APA | Fu, XD,Wang, GQ,&Shao, XJ.(2010).Vertical disoersion of fine and coarse sediments in turbulent open-channel flows.. |
MLA | Fu, XD,et al."Vertical disoersion of fine and coarse sediments in turbulent open-channel flows".(2010). |
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