Optimization of Threshold Velocity Values for Sediment Transport at the Outer Bank of a 180-Degree Bend with Emergent Vegetation DOI Open Access

Nasim Rismani,

Hossein Afzalimehr,

Seyed Amin Asghari Pari

et al.

Water, Journal Year: 2025, Volume and Issue: 17(7), P. 971 - 971

Published: March 26, 2025

The interaction between curvature-induced flow and vegetation plays a crucial role in regulating threshold velocity, influencing sediment transport dynamics. This experimental study investigates the effects of velocity turbulence, induced by both emergent curvature-driven flow, on motion around vegetated patch. Using an Acoustic Doppler Velocimeter (ADV), total 504 profiles were collected under non-vegetated conditions, considering range densities (φ = 0.001–0.0099) straight channel 180-degree bend. results indicate that modifies turbulent kinetic energy (TKE) gradients, thereby enhancing mobility. Specifically, significantly reduces maximum up to 37%, shifting core center TKE 30 times. analysis shows curvature contributes 34% 17% first second halves bend, respectively. Turbulence from bed accounts for 50% paths, while curved it reaches 37% 32% half 48% 42% proposes model (kt) incorporates constraints, validated through controlled laboratory experiments, highlighting near-bed turbulence modulating transport. Furthermore, findings demonstrate initiation is governed mean TKE, leading introduction novel criterion assessing initial conditions flows.

Language: Английский

Optimization of Threshold Velocity Values for Sediment Transport at the Outer Bank of a 180-Degree Bend with Emergent Vegetation DOI Open Access

Nasim Rismani,

Hossein Afzalimehr,

Seyed Amin Asghari Pari

et al.

Water, Journal Year: 2025, Volume and Issue: 17(7), P. 971 - 971

Published: March 26, 2025

The interaction between curvature-induced flow and vegetation plays a crucial role in regulating threshold velocity, influencing sediment transport dynamics. This experimental study investigates the effects of velocity turbulence, induced by both emergent curvature-driven flow, on motion around vegetated patch. Using an Acoustic Doppler Velocimeter (ADV), total 504 profiles were collected under non-vegetated conditions, considering range densities (φ = 0.001–0.0099) straight channel 180-degree bend. results indicate that modifies turbulent kinetic energy (TKE) gradients, thereby enhancing mobility. Specifically, significantly reduces maximum up to 37%, shifting core center TKE 30 times. analysis shows curvature contributes 34% 17% first second halves bend, respectively. Turbulence from bed accounts for 50% paths, while curved it reaches 37% 32% half 48% 42% proposes model (kt) incorporates constraints, validated through controlled laboratory experiments, highlighting near-bed turbulence modulating transport. Furthermore, findings demonstrate initiation is governed mean TKE, leading introduction novel criterion assessing initial conditions flows.

Language: Английский

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