Randomness representation of Turbulence in an alluvial channel affected by downward seepage

2018 ◽  
Vol 509 ◽  
pp. 74-85 ◽  
Author(s):  
Anurag Sharma ◽  
Dragutin T. Mihailović ◽  
Bimlesh Kumar
Keyword(s):  
Downward Seepage ◽  
Alluvial Channel

Double averaged turbulence characteristics of alluvial channel with downward seepage

2018 ◽  
Vol 45 (2) ◽  
pp. 135-151 ◽  
Author(s):  
Anurag Sharma ◽  
Bimlesh Kumar
Keyword(s):  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Seepage Flow ◽  
Quadrant Analysis ◽  
Turbulence Characteristics ◽  
Downward Seepage ◽  
Turbulent Statistics ◽  
Alluvial Channel ◽  
Bursting Events ◽  
Flow Turbulence

Present work evaluates the double averaged turbulence characteristics of the sand bed channel subjected to the downward seepage through permeable bed. Measures of turbulent statistics are observed to increase with the application of downward seepage. The form induced stress in near bed has a reducing effect with no seepage and an increasing effect with seepage. The seepage increases the turbulent kinetic energy and turbulent intensities causing the bed particles to move rapidly. The quadrant analysis suggests that at near bed, the sweep events in flows with seepage are the main bursting events towards the Reynolds stress production, while ejection and sweep events in no seepage flow have almost equal contribution. The increase in sediment transport with seepage is caused by an increase in flow turbulence production and an associated decrease in turbulent kinetic energy dissipation and turbulent diffusion.

Flow and bedform dynamics in an alluvial channel with downward seepage

CATENA ◽  
2017 ◽  
Vol 158 ◽  
pp. 219-234 ◽  
Author(s):  
Mahesh Patel ◽  
Bimlesh Kumar
Keyword(s):  
Downward Seepage ◽  
Alluvial Channel

scholarly journals Statistical description of morphological characteristics of bedforms in seepage affected alluvial channels

2018 ◽  
Vol 45 (2) ◽  
pp. 87-98
Author(s):  
Mahesh Patel ◽  
Shantanaba Majumder ◽  
Bimlesh Kumar
Keyword(s):  
Morphological Characteristics ◽  
Wave Number ◽  
Alluvial Channels ◽  
Cross Sectional ◽  
Bed Elevation ◽  
Power Spectral ◽  
Downward Seepage ◽  
Alluvial Channel ◽  
Multi Temporal ◽  
Channel Boundary

In this study, experiments were performed in a curvilinear cross-sectional threshold alluvial channel with no seepage and with seepage conditions to understand the influence of downward seepage in an alluvial channel. We observed that a stable channel during the no seepage condition started to approach a stable channel in the transporting stage with downward seepage. Increased value of Shields stress was observed after the application of seepage. In addition, this study deals with the effect of downward seepage on the evolution of alluvial bedforms. In this regard, multi-temporal bed elevation profiles were collected along the test section of channel, which are used to characterize migrating bedforms. Results reveal greater fluctuations and variability on the channel bed under the influence of increased seepage discharge. Slope of the power spectral density with wave number was significantly increased with an increment in seepage percentage, showing more inhomogeneous arrangement of bedforms and larger roughness over the channel boundary.

scholarly journals Hydrodynamics of submerged vegetated alluvial channel with downward seepage

2017 ◽  
Vol 44 (3) ◽  
pp. 174-181 ◽  
Author(s):  
Thokchom Bebina Devi ◽  
Bimlesh Kumar
Keyword(s):  
Oryza Sativa ◽  
Flow Velocity ◽  
Reynolds Stress ◽  
Time Scales ◽  
Flow Conditions ◽  
Vegetation Zone ◽  
Flow Measurements ◽  
Downward Seepage ◽  
Alluvial Channel ◽  
Zone Centre

The flow conditions in a channel covered with fully submerged Oryza sativa has been investigated considering downward seepage. The flow measurements taken at the upstream free vegetation zone, centre of the vegetation zone, and downstream free vegetation zone will provide a better understanding regarding the flow hydrodynamics in a vegetated channel. The flow velocity, Reynolds stress, and turbulent intensities are reduced at the downstream vegetated section. Downward seepage increases the occurrence of streamwise flux along the length of the channel and vertical flux in the vertically downward direction. Integral length and time scales increase as the percentage of downward seepage increases.

Downward seepage effects on dynamics of scour depth and migrating dune-like bedforms at tandem piers

2020 ◽  
Vol 47 (1) ◽  
pp. 13-24
Author(s):  
Rutuja Chavan ◽  
Bimlesh Kumar
Keyword(s):  
Experimental Approach ◽  
Scour Depth ◽  
Statistical Characterization ◽  
Multi Scale ◽  
Bed Elevation ◽  
Downward Seepage ◽  
Alluvial Channel ◽  
Reversal Flow ◽  
Erosive Capacity

The present study focuses on multi-scale statistical characterization of scour depth at tandem piers and migrating dune-like bedforms forming behind the piers in downward seepage affected alluvial channel, using an experimental approach. Experiments were conducted using two circular piers arranged in a tandem manner for no seepage, 10% seepage, and 15% seepage condition. The erosive capacity of reversal flow is hindered with downward seepage, which results in reducing velocity and Reynolds stress near the bed at upstream of piers in case of seepage runs. The bed elevation of the scoured region is decreasing with the increasing seepage percentage and the growth in scour depth is diminishing with time. The celerity of scour depth is decreasing with time as well as decreasing with increasing downward seepage. Probability density function of bedform elevation has positive tail slightly thicker than the Gaussian.

Achieving Equilibrium as a Semi‐Alluvial Channel: Anthropogenic, Bedrock, and Colluvial Controls on the White Clay Creek, PA, USA

2021 ◽  
Vol 126 (10) ◽  
Author(s):  
Sophie Bodek ◽  
James E. Pizzuto ◽  
Kristen E. McCarthy ◽  
Raphael A. Affinito
Keyword(s):  
Alluvial Channel ◽  
White Clay
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