Prediction of erosion intermittency using Large Eddy Simulation

Abstract

The present CFD (Computational Fluid Dynamics) study investigates the triggering of aeolian erosion, which takes place on two transverse sand piles placed in tandem. The URANS (Unsteady Reynolds-averaged Navier-Stokes), DES (Detached Eddy Simulation) and LES (Large Eddy Simulation) approaches are evaluated on their prediction capability of the friction velocity. Each predicted friction velocity is evaluated against a proposed threshold condition, which considers the surface slope along with the near-surface flow direction to be compliant with established recirculation regions.The DES and LES approaches are found to be capable of predicting aeolian erosion intermittency, a phenomenon characterized by burst activity. The URANS approach, by yielding a nearly steady-state solution, predicts erosion only on a time-averaged basis. DES and LES approaches corroborate the reshaping observed in the wind tunnel tests, where the erosion is substantial on the leeward pile and insignificant on the windward one.