Study of unsteady nonequilibrium stratified suspended sediment distribution in open-channel turbulent flows using shifted Chebyshev polynomials

2020 ◽  
pp. 1-11
Author(s):  
Snehasis Kundu
Keyword(s):  
Suspended Sediment ◽  
Turbulent Flows ◽  
Chebyshev Polynomials ◽  
Open Channel ◽  
Sediment Distribution

Two-phase modeling of suspended sediment distribution in open channel flows

2004 ◽  
Vol 42 (3) ◽  
pp. 273-281 ◽  
Author(s):  
Junsheng Jiang ◽  
Adrian Wing-Keung Law ◽  
Nian-Sheng Cheng
Keyword(s):  
Suspended Sediment ◽  
Open Channel ◽  
Channel Flows ◽  
Open Channel Flows ◽  
Two Phase ◽  
Sediment Distribution

scholarly journals Suspended sediment distribution under varied currents in the largest river-connected lake of China

2017 ◽  
Vol 18 (3) ◽  
pp. 994-1004 ◽  
Author(s):  
Hua Wang ◽  
Yijun Zhao ◽  
Fengnian Zhou ◽  
Huaiyu Yan ◽  
Yanqing Deng ◽  
...  
Keyword(s):  
Flow Pattern ◽  
Suspended Sediment ◽  
Flow Patterns ◽  
Field Investigation ◽  
Gravity Flow ◽  
Shear Stresses ◽  
Sediment Distribution ◽  
Back Flow ◽  
The North ◽  
Dry Seasons

Abstract Poyang Lake was selected as the research area. Based on laboratory experiment, field investigation and numerical simulation, the spatial distributions of suspended sediment (SS) under the gravity-flow, jacking-flow and back-flow patterns were quantitatively analysed. An annular flume experiment was conducted to determine the critical starting shear stresses of the sediments in the flood and dry seasons. By numerical experiment, the SS transport under different flow patterns was explored. Several results stand out. (1) The critical starting shear stresses of the sediments in the flood and dry seasons were 0.35 N·m−2 and 0.29 N·m−2, respectively. (2) Due to the strongest flow disturbance and scouring effect, SS under the gravity-flow pattern was characterized by the highest loads. The lowest SS was observed during the jacking-flow pattern, which could be attributed to the lowest water level gap between the lake and external rivers. The loads ranged from 0.053 kg·m−3 to 0.068 kg·m−3. (3) Under the back-flow pattern, SS in the north lake was evidently influenced by the Yangtze River, and the mean value was approximately 0.12 kg·m−3. With the gradually weakened back-flow impact, the SS load was decreased from the north to the middle of the lake.

scholarly journals Direct numerical simulation of intermittent turbulence under stably stratified conditions

2015 ◽  
Vol 2 (1) ◽  
pp. 179-241 ◽  
Author(s):  
P. He ◽  
S. Basu
Keyword(s):  
Numerical Simulation ◽  
Direct Numerical Simulation ◽  
Turbulent Flows ◽  
Open Channel ◽  
Temporal Evolution ◽  
Intermittent Turbulence ◽  
Bursting Events ◽  
Spatio Temporal ◽  
Channel Region ◽  
Laminar And Turbulent Flows

Abstract. In this paper, we simulate intermittent turbulence (also known as bursting events) in stably stratified open-channel flows using direct numerical simulation. Clear signatures of this intriguing phenomenon are observed for a range of stabilities. However, the spatio-temporal characteristics of intermittency are found to be strongly stability-dependent. In general, the bursting events are much more frequent near the bottom wall than in the upper-channel region. A steady coexistence of laminar and turbulent flows is detected at various horizontal planes in very stable cases. This spatially intermittent pattern is found to propagate downstream and strongly correlate with the temporal evolution of intermittency. Last, a long standing hypothesis by Blackadar, i.e., the strong connection between local stability and intermittent turbulence, is corroborated by this modeling study.

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