Study of sediment transport in the saltation regime

TL;DR

This study models sediment transport in the saltation regime using particle simulations and fluid flow profiles, revealing how saturated flux varies with flow strength under different flow conditions.

Contribution

It introduces a particle-based simulation approach with different fluid velocity profiles to analyze sediment transport in saltation and creeping regimes.

Findings

Saturated flux increases quadratically with flow strength for turbulent flow.

Saturated flux increases cubically with flow strength for laminar flow.

Velocity distribution functions help interpret transport behavior.

Abstract

We present a study of sediment transport in the creeping and saltation regime. In our model, a bed of particles is simulated with the conventional event-driven method. The particles are considered as hard disks in a 2d domain, with periodic boundary conditions in horizontal direction. The flow of the fluid over this bed of particles is modeled by imposing a force on each particle that depends on the velocity of the fluid and its height above the bed. We considered two velocity profiles for the fluid, parabolic and logarithmic. The first one models laminar flow and the second corresponds to turbulent flow. For each case we investigated the behavior of the saturated flux. We found that for the logarithmic profile, the saturated flux shows a quadratic increase with the strength of the flow, and for parabolic profile, a cubic increase. The velocity distribution functions are used to interpret the results.