Discrete Element Method simulations of the saturation of aeolian sand transport

@article{Pahtz2015DiscreteEM,
  title={Discrete Element Method simulations of the saturation of aeolian sand transport},
  author={Thomas Pahtz and Amir Omeradvzi'c and Marcus Vinicius P. Carneiro and Nuno A. M. Ara'ujo and Hans J{\"u}rgen Herrmann},
  journal={Geophysical Research Letters},
  year={2015},
  volume={42},
  pages={2063 - 2070}
}
The saturation length of aeolian sand transport (Ls), characterizing the distance needed by wind‐blown sand to adapt to changes in the wind shear, is essential for accurate modeling of the morphodynamics of Earth's sandy landscapes and for explaining the formation and shape of sand dunes. In the last decade, it has become a widely accepted hypothesis that Ls is proportional to the characteristic distance needed by transported particles to reach the wind speed (the “drag length”). Here we… 

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References

SHOWING 1-10 OF 59 REFERENCES

Minimal model for aeolian sand dunes.

We present a minimal model for the formation and migration of aeolian sand dunes in unidirectional winds. It combines a perturbative description of the turbulent wind velocity field above the dune

Measurements of the aeolian sand transport saturation length

The apparent roughness of a sand surface blown by wind from an analytical model of saltation

We present an analytical model of aeolian sand transport. The model quantifies the momentum transfer from the wind to the transported sand by providing expressions for the thickness of the saltation

Continuum saltation model for sand dunes.

It is pointed out that saturation transients are indispensable for a proper description of sand flux over structured terrain, by applying the model to the windward side of an isolated dune, thereby resolving recently reported discrepancies between field measurements and theoretical predictions.

Aeolian transport of sand

A new relation for fluxes close to the threshold velocity ut, namely, qs=a(u*-ut)α with α≈2 with a novel dynamical scaling relation is proposed and explained.

Direct numerical simulations of aeolian sand ripples

Direct numerical simulations of grains interacting with a wind flow are reported, for the first time to the authors' knowledge, able to reproduce the spontaneous growth of ripples with an initial wavelength and a propagation velocity linearly increasing with the wind speed.

The fluctuation property of blown sand particles and the wind-sand flow evolution studied by numerical method

The results indicate that the saturation time decreases with the inlet friction velocity, and it gradually reaches the shortest saturation time of about 1s; the saturation length, which is about 14 m at the usual wind velocity, first increases with wind velocity and then reaches a plateau; within the saturationlength, the sand transport rate at different positions varies with time.

A two-species continuum model for aeolian sand transport

Starting from the physics on the grain scale, we develop a simple continuum description of aeolian sand transport. Beyond popular mean-field models, but without sacrificing their computational
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