Aeolian transport layer

TL;DR

This paper uses numerical simulations to study airborne particle transport on granular surfaces, proposing new relations for flux and saltation layer height that align with empirical data and extend understanding of wind-driven particle movement.

Contribution

It introduces a new flux relation for small fluxes and provides a novel expression for saltation layer height based on wind velocity, advancing the modeling of aeolian transport.

Findings

Validated classical empirical flux relation with simulations

Proposed a new flux relation for small fluxes with a scaling exponent of approximately 2

Derived a new expression for saltation layer height as a function of wind velocity

Abstract

We investigate the airborne transport of particles on a granular surface by the saltation mechanism through numerical simulation of particle motion coupled with turbulent flow. We determine the saturated flux $q_{s}$ and show that its behavior is consistent with a classical empirical relation obtained from wind tunnel measurements. Our results also allow to propose a new relation valid for small fluxes, namely, $q_{s}=a(u_{*}-u_{t})^{\alpha}$, where $u_{*}$ and $u_{t}$ are the shear and threshold velocities of the wind, respectively, and the scaling exponent is $\alpha \approx 2$. We obtain an expression for the velocity profile of the wind distorted by the particle motion and present a dynamical scaling relation. We also find a novel expression for the dependence of the height of the saltation layer as function of the wind velocity.