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Indexed by:期刊论文

Date of Publication:2008-08-01

Journal:SCIENCE IN CHINA SERIES G-PHYSICS MECHANICS & ASTRONOMY

Included Journals:SCIE、EI、Scopus

Volume:51

Issue:8

Page Number:945-960

ISSN No.:1672-1799

Key Words:large-eddy simulation; equation of spherule motion; sand ripples; saltation; creep

Abstract:With the method of large-eddy simulation, the equation of spherule motion and the method of immersed boundary condition, numerical simulations of three-dimensional turbulent aeolian motion and the formation of sand ripples under three-dimensional turbulent wind and the mutual actions of saltation and creeping motion were carried out. The resulting sand ripples have the form that is flat on the upwind side and steep on the leeward, which is identical to the sand ripples in nature. We also realized the self-restoration process of three-dimensional sand ripples, which shows the correctness of the method of numerical simulation and the models of saltation and creeping. Finally, We analyzed the influence of sand ripples on the three-dimensional turbulent wind field, and found that due to the appearance and development of sand ripples, in the normal direction of ground there exists stronger energy exchange, and moreover, there is close correspondence between the forms of sand ripples and the vorticity close to the ground surface.