A three-dimensional analysis on lift-off velocities of sand grains in wind-blown sand flux

ICAR 6 : Aeolian processes. Special issue

Auteur(s) et Affiliation(s)



Description :
This paper focuses on a key problem in wind-blown sand transport research, the lift-off velocities of sand grains. A three-dimensional grain-bed collision model comprising an impact sand grain, a creeping sand grain and a sustaining grain is presented. Based on this model, the analytical formulae of sand grains'linear and angular velocities are derived. Comparisons of the results with the results gained by a two-dimensional grain-bed collision model show that all components of both rebound and ejected velocities gained by the three-dimensional model are lower than the corresponding ones done by two-dimensional model apart from the horizontal rebound velocity. It also shows the lateral velocity and the lateral angular velocity, as well as the upward angular velocity, cannot be obtained by a two-dimensional model, and cannot be ignored when the impact velocity is high.


Type de document :
Congrès

Source :
Internat. Conf. on Aeolian Research (ICAR 6), 6, Guelph, Canada, 2006-07-24/2006-07-26, Earth surface processes and landforms, issn : 0197-9337, 2008, vol. 33, n°. 12, p. 1824-1838, nombre de pages : 15, Références bibliographiques : 20 ref.

Date :
2008

Editeur :
Pays édition : Royaume-Uni, Chichester, Wiley