Dynamics of meandering rivers in finite-length channels: linear theory

نویسندگان

چکیده

Meandering channels are dynamic landforms that arise as a result of fluid mechanic and sedimentary processes. Their evolution has been described by the meander-morphodynamic equations, which dictate channel curvature bed topography give rise to local perturbations in streamwise velocity, prompting preferential erosion sediment deposition constitute meander behaviour. Novel mathematical conditions presented guarantee unique solutions for linearized equations non-periodic domains with finite boundaries. With boundary condition specification sufficient uniqueness proof one finds well-posed initial-boundary-value problem amenable standard numerical techniques partial differential equations. This provides pathway improved algorithms simulations meandering river dynamics. Previous theoretical analysis linear stability theory dynamics restricted spatially periodic systems. The present effort develops new results systems temporal driving at system boundaries well non-homogeneous initial conditions. Predictions inlets provide clarification observed behaviour laboratory flumes where driven inlet avoids long-term decay all meanders fixed entry Linear confirms continuous perturbation is required sustained meandering. Original scaling arguments dependence migration rate on geological parameters, showing increases increased width, downreach slope bank erodibility, decreases volumetric flow rate.

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ژورنال

عنوان ژورنال: Journal of Fluid Mechanics

سال: 2022

ISSN: ['0022-1120', '1469-7645']

DOI: https://doi.org/10.1017/jfm.2022.131