Anomalous Scaling of Aeolian Sand Transport Reveals Coupling to Bed Rheology
arXiv:2302.02067 · doi:10.1103/PhysRevLett.130.058204
Abstract
Predicting transport rates of windblown sand is a central problem in aeolian research, with implications for climate, environmental, and planetary sciences. Though studied since the 1930s, the underlying many-body dynamics is still incompletely understood, as underscored by the recent empirical discovery of an unexpected third-root scaling in the particle-fluid density ratio. Here, by means of grain-scale simulations and analytical modeling, we elucidate how a complex coupling between grain-bed collisions and granular creep within the sand bed yields a dilatancy-enhanced bed erodibility. Our minimal saltation model robustly predicts both the observed scaling and a new undersaturated steady transport state that we confirm by simulations for rarefied atmospheres.
References in corpus (6)
- The physics of sediment transport initiation, cessation, and entrainment across aeolian and fluvial environments
- Power-law scaling in granular rheology across flow geometries
- A two-species continuum model for aeolian sand transport
- A lower-than-expected saltation threshold at Martian pressure and below
- The fluctuation energy balance in non-suspended fluid-mediated particle transport
- Scaling laws for planetary sediment transport from DEM-RANS numerical simulations