Shallow turbulent mixing layers in open-channel flows

Environmental Fluid Mechanics, Journal Year: 2025, Volume and Issue: 25(1)

Published: Jan. 15, 2025

Abstract A mixing layer (ML) forms when two streams of different speeds or densities merge. MLs are ubiquitous in nature and can be often observed the atmosphere, ocean, rivers, canals, lakes reservoirs. This review paper focuses on turbulent developing open-channel flows vertical size ML is smaller than its streamwise spanwise dimensions. Such referred to as shallow (SMLs). The SMLs involve large-scale features such quasi-two-dimensional coherent structures with a bed-normal axis, streamwise-oriented vortices, secondary currents, gravity bed-induced large- very-large-scale motions. Considering various types SMLs, we distinguish driven by (i) inhomogeneity hydrodynamic parameters, (ii) lateral changes flow resistance, (iii) heterogeneity fluid density. As associated largely control transverse exchanges substances (e.g., sediments, pollutants, nutrients) heat, thermal also addressed. Then, commonalities differences among identified. concluded suggestions future research efforts for advancing knowledge capabilities their predictions control.

Language: Английский

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Effects of stratification on hydrodynamics and mixing process at a large asymmetric confluence in northern China

Journal of Contaminant Hydrology, Journal Year: 2025, Volume and Issue: 270, P. 104531 - 104531

Published: Feb. 26, 2025

Language: Английский

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Hydraulic complexity at a laboratory-scale confluence: Experimental distribution of bioenergetics metrics and its relation to Yangtze finless porpoise habitats

Physics of Fluids, Journal Year: 2025, Volume and Issue: 37(4)

Published: April 1, 2025

Confluences are key features in river networks and serve as critical nodes for ecological patterns, often exhibiting rich biodiversity. However, our current understanding of how hydrodynamics influences these patterns remains limited, most previous studies have focused on factors alone. This study applied a Particle Image Velocimetry system to investigate the spatial distribution hydraulic complexity metrics (M1, M2, M4) laboratory-scale confluence under both steady unsteady flow conditions. These metrics, derived from velocity measurements, been characterize aquatic species abundance, richness, motion. M1 was found effectively delineate different hydrodynamic zones confluence, peaking within shear layer. Additionally, can identify boundary areas with steep gradients inside separation zone. Field observations finless porpoises at various confluences Yangtze River suggested that tend prefer low M1, such stagnation during flood season, more generally area dry season. preference is likely related their feeding. The contributed better dynamics Basin, well conservation endangered porpoise.

Language: Английский

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Prediction of polydisperse particles deposition and mean flow structures at a bifurcating channel using an Euler–Lagrange approach

Environmental Fluid Mechanics, Journal Year: 2025, Volume and Issue: 25(2)

Published: April 1, 2025

Language: Английский

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