The effects of slope and slope position on local and upstream fluid threshold friction velocities

Abstract

AbstractIn deserts, dunes are common aeolian landforms, and parallel ridges are common in cultivated land. A computational fluid dynamics (CFD) model is used to simulate a stable wind blowing over slope beds of varying height and coupled with the slope‐compensating fluid threshold friction velocity formula. The model accurately reproduced patterns of flow deceleration at the slope toe and stoss flow acceleration. Based on the CFD‐based model, quantitative analyses of slope gradient and particle position on the initiation of particle movement are performed. Results indicate that the slope has a great influence on particle saltation in the windward slope, and the initiation of particle movement is particularly sensitive to particle position with respect to the slope. Copyright © 2008 John Wiley & Sons, Ltd.