Sediment Transport in Unsteady Flow Conditions

A simple model of unsteady sheet-flow sediment transport

A simple, quasi-steady, one-dimensional, vertical (1DV) model of unsteady sheet flow is presented. The central aim is to provide greater realism in the near-bed, high-concentration layer, than is possible using models based on the classical referenceconcentration approach. This is achieved by tracking erosion and deposition at the bottom of the mobile sediment layer in relation to the amount of...

Investigation of unsteady and non-uniform flow and sediment transport characteristics at culvert sites

Sediment Transport and Dunes in Pipe Flow

We propose a two-phase model having a Newtonian rheology for the fluid phase and friction for the particle phase to describe bed-load transport in laminar pipe flows. This model is able to provide a description of the flow of the mobile granular layer. When the flow is not significantly perturbed, simple analytical results of the particle flux varying cubically with the Shields number can be ob...

The Effect of Convergence and Divergence on Flow Pattern and Sediment Transport in Lateral Intakes

Water supply at a desired rate at any time to meet the water requirements regardless of river discharge must be considered in the general design of intakes provided that the needs do not exceed the river flow. Due to the lack of necessary information in this field and the importance of sediment transport to the lateral intakes at river bends, this study aimed at understanding the mechanism of t...

Generalized characteristic relaxation boundary conditions for unsteady compressible flow simulations

We develop numerical boundary conditions for the compressible Navier–Stokes equations based on a generalized relaxation approach (GRCBC), which hinges on locally one-dimensional characteristic projection at the computational boundaries, supplemented with available information from the flow exterior. The basic idea is to estimate the amplitude of incoming characteristic waves through first-order...

Unsteady Squeezing Flow of Carbon Nanotubes with Convective Boundary Conditions

Unsteady flow of nanofluids squeezed between two parallel plates is discussed in the presence of viscous dissipation. Heat transfer phenomenon is disclosed via convective boundary conditions. Carbon nanotubes (single-wall and multi-wall) are used as nanoparticles which are homogeneously distributed in the base fluid (water). A system of non-linear differential equations for the flow is obtained...