Numerical Modeling for Sand Desert Morphology and Forming Process in Fixed, Semi-Fixed and Free Desert Field

Abstract

In this study, to conduct numerical simulation of desert physiognomy forming process in fixed, semi-fixed and free sand desert field by considering the sand flow process by wind, the numerical model based on the hydrodynamics and sand grains kinemics are proposed. For analyze the actual characteristic of sand movement phenomenon, the stream flow field and desert flow field are introduced and mathematical model for numerical analysis are established by considering the sand shape, size and mass in order to describe the fixed, semi-fixed and fully free sand desert physiographical process. Then according to the real fixed, semi-fixed and free sand flow field by coupling with stream flow field, several models are made and numerical simulations are conducted.

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.…”

“…The salting grains travel by making long jumps and the repeating grains move in hopping manner over a much smaller distance [6]. In this paper, for computational simulation of the sand morphology forming process by wind, a new mathematical model [7] which is established based on the sand ripples model proposed by Nishimori and Ouchi [4] and Miao et al [5] is used mainly to set out the two flow fields from the theoretical analysis and introduce the air flow field and sand flow field constitutive equation, and weakly coupling methods for air and sand flow field are analyzed by modifying sand ripple forming process by considering the uniform and nonuniform complex sand flow area.…”

“…where 0 is base value of jumping distance of sand particles, which is jump along the , , directions and correlated with wind power. ℎ is the height of the grain position, is wind velocity, is sand grains critical wind velocity for jumping (in this papers use 0.2 m/s), and are the average mass and diameter of the sand grains, is grains shape coefficient (take it 1.0 for spherical), and are the density of the air and sand, and is resistance coefficient [7]. Take the equations from (9), (10) and (11) into (8) and introduce the relation of jumping time step Δ and obtain the following equation:…”

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

“…The 1/4 of the world land and 1/6 of the population of the world are suffering from the desertification. The prevention and control the desertification is one of the key problems, and it is very important to conduct the study of desertification, especially how to globally control and predict the desertification and mechanism of the sand movement by considering the fixed, semi-fixed and free sand desert field [2][3][4][5].…”

SPH Method for Simulation of Wind-Blown Sand Movements

“…At present, there are cellular automata method [1], coupled mapping lattice method [2] and discrete element method [3], which is used in numerical simulation for sand ripple and wind-blown sand movement [4][5][6][7][8]. These computational simulation methods based on combine dispersibility of sand and discrete model is their common character.…”