Hydrodynamics and bed morphology in a double-layered partially vegetated mobile bed channel

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(3)

Published: March 1, 2025

This study investigates the hydrodynamics and sediment transport in a double-layered partially vegetated mobile bed channel, focusing on impact of submerged vegetation with submergence ratio 61.53% 30.77% flow dynamics morphology. Experiments were conducted straight, tilting rectangular flume staggered double layered covering half channel width. The three dimensional time-averaged velocity components, turbulent intensities, secondary current, kinetic energy, Reynolds shear stress are measured analyzed using contour plots along outcomes reveal that induces significant momentum exchange between non-vegetated sections. In section, dampens streamwise intensity near bed, promoting deposition enhancing stability. Momentum transfer at interface strengthens shear, increasing turbulence leading to greater erosion. Negative streamwise-vertical indicates helical flow, while transverse-vertical peaks bed. Flow diversion intensifies erosion high-energy vegetation-induced drag decelerates causing transition deeper section. Double-layered rivers or canals is more effective stabilizing materials. These findings provide critical insight for river restoration management, emphasizing necessity integrated management strategies balance across heterogeneous environments.

Language: Английский

Impact of mixed-height vegetation patches on energy loss in open-channel flow

Scientific Reports, Journal Year: 2025, Volume and Issue: 15(1)

Published: April 1, 2025

Abstract This study investigates the influence of riparian vegetation on energy losses in open-channel flow, focusing channels partially covered by mixed-height patches, a common feature natural rivers and canals. While previous research has primarily focused flow resistance fully vegetated channels, there been limited attention to with unevenly distributed patches. To address this gap, we developed an innovative experimental approach evaluate loss patches under different submergence conditions. The setup involved channel varying heights, mimicking natural, uneven distribution results provided key insights into velocity turbulence intensity these Furthermore, introduced standardized conceptualization method for ratio, specifically concept effective height ( $${h}_{e}$$ ), standardize calculation methods submerged emergent vegetation.Using parameter, derived theoretical formula calculating caused which closely matched data. offers reliable framework hydraulic distribution.

Language: Английский

Quasi-three-dimensional calculation modeling to simulate flows and sediment transport in channels partially covered with emergent rigid vegetation

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(6)

Published: June 1, 2025

Flows in channels partially covered with vegetation have attracted attention due to their complex phenomena, including formations of large coherent structures and secondary flows, enhancing three-dimensional flow characteristics. In this paper, we developed validated a quasi-3D calculation (quasi-3DC) model that incorporates vortex motions (3DVM) into two-dimensional framework as sub-grid simulate flows sediment transport strongly curved meandering vegetation. Before calculations under movable bed conditions, through comparisons results from experiments, (2DC), (3DC) better understand the impact 3DVM. The study demonstrated quasi-3DC accurately predicted structures, velocity distribution, maximum velocity, patterns, emphasizing importance considering Afterward, based on account for effects turbulent kinetic energy effective bottom shear stress simulating dynamics vegetated channels. showed promising results, especially capturing scouring front areas.

Language: Английский