Numerical Study on Aeolian Sand Ripples Forming and Moving Process in Desert Highway

Abstract

In this paper, the sand break into highway problem in desert, which is caused by the sand flow blown by wind, is studied. The mathematical models are introduced by considering the fixed, semi-fixed and free sand desert fields based on the fluid dynamics and the sand particle dynamics. Different kinds of numerical models are made by changing the desert highway height, wind flow direction and its uniformity. The weak coupling method is used due to spatial relationships between air flow field and the sand flow field. Finally, by coupling the airflow field and sand flow field with desert highway, the numerical simulations of sand forming process on desert highway are conducted. The numerical results shown, that the wind blown sand breaks into highway easier when wind direction perpendicular highway and if the highway height higher than the range size of the sand surface the wind blown sand break into highway is more difficult.

Numerical Modeling and Simulation of Wind Blown Sand Morphology under Complex Wind-Flow Field

“…Equation (12) expresses the main movement of the sand suspension and saltation form; due to limitation, the discussion of sand creep and avalanche phenomenon are ignored and the Nishimori and Ouchi [4] and Miao et al [5] method are directly used. Some interesting and reasonable numerical results are obtained [7][8][9][10]. In this study similar numerical methods are used for airflow and sand flow field.…”

Simulation of Sand Particles Flow Using a Weakly Compressible Smoothed Particle Hydrodynamics Method (WCSPH)

“…The values of yield stress and viscous coefficient of the Bingham fluid for modeling sand is according to Ref. [20] which are selected after try and error to have the best values for our studied sand. Reminding that two kinds of sand are studied, different values for yield stress = 200 Pa and = 1000 Pa with constant Two types of costal beds which are defined and distinguished from each other by their difference in value of yield stress are shown in Figure 28.…”

“…Obviously, in higher values than yield stress, the fluid continuously introduces strain. The stress relation in this model is as follows [20]:…”

“…Abdikerem et al [19] numerically studied the sand ripple formation process under uniform and nonuniform airflow and revealed that the nonuniform airflow creates the complex curved ripples. Aeolian sand ripples formation in desert highway was investigated by Ablimit et al [20] by using the weak coupling method. They found that the break of sands into highway depends on the highway height.…”