Channel instability in a braided, sand bed river

Longitudinal variability in hydraulic geometry and substrate characteristics of a Great Plains sand-bed river

Mathematical Modeling of Flow in a Granular Permeable Bed Channel

In this research, a two-dimensional mathematical model using  turbulence model was developed in a rectangular channel with granular permeable bed. Finite volume method was used for numerical solution of governing equations. The equations considered are discretized using Hybrid difference scheme while applying SIMPLE algorithm to correct velocity components in the continuity equation. In the dev...

Do gravel bed river size distributions record channel network structure?

[1] Bed load sediment particles supplied to channels by hillslopes are reduced in size by abrasion during downstream transport. The branching structure of the channel network creates a distribution of downstream travel distances to a given reach of river and thus may strongly influence the grain size distribution of the long-term bed load flux through that reach. Here we investigate this hypoth...

Fingering Instability in a Water-Sand Mixture

The temporal evolution of a water-sand interface driven by gravity is experimentally investigated. By means of a Fourier analysis of the evolving interface the growth rates are determined for the different modes appearing in the developing front. To model the observed behavior we apply the idea of the Rayleigh-Taylor instability for two stratified fluids. Carrying out a linear stability analysi...

Surface instability in windblown sand.

We investigate the formation of ripples on the surface of windblown sand based on the one-dimensional model of Nishimori and Ouchi [Phys. Rev. Lett. 71, 197 (1993)], which contains the processes of saltation and grain relaxation. We carry out a nonlinear analysis to determine the propagation speed of the restabilized ripple patterns, and the amplitudes and phases of their first, second, and thi...