干旱区研究

Arid Zone Research ›› 2018, Vol. 35 ›› Issue (1): 107-113.doi: 10.13866/j.azr.2018.01.13

• Application Climate • Previous Articles     Next Articles

SPH-based Numerical Calculation of Sand Grain Velocity Distribution in Wind-blown Sand Flow

JIN A-fang1, Maimtimin Ayni1, HU Guo-yu1, XIONG Min2, MA Xiao-jing3   

  1. 1. College of Mechanical Engineering,Xinjiang University,Urumqi 830047,Xinjiang,China;
    2. College of Resources and Environmental Science,Xinjiang University,Urumqi 830047,Xinjiang,China;
    3. College of Electricals Engineering,Xinjiang University,Urumqi 830047,Xinjiang,China
  • Received:2016-12-05 Revised:2017-08-28 Online:2018-01-15 Published:2025-11-16

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Abstract: The wind-blown sand movement is a kind of air-sand two-phase flow problem.Under the action of air flow,sand grains experience a lift-off when they are changed from static state to movement.The research on lift-off of sand is very important in physics of wind-blown sand,and the distribution of the lift-off speed and the lift-off angle are the main physical factors and play an important role in deciding the motion state of sand in air.There are three types of sand movement in air flow,such as creep,suspension and saltation.Among them,the saltation accounts for about 75% of the wind-blown sand movement types.Tomaster mechanism of saltation can help us understand the law of wind-blown sand movement,and it can be used to further improve the study on the physics of wind-blown sand.There are two main reasons for the lift-off of sand,i.e.,fluid starting driven directly by air flow and the impact starting caused by other sand grains.Speed distribution function of sand can reflect the information of the macro-scale movement and the micro-scale movement in wind-blown sand movement.To determine the speed distribution function of the sand can work out the various macro-scale statistical variables.The Smoothed Particle Hydrodynamics (SPH) method,a Lagrange Particle method,was applied in this paper to dissect the mathematical model of wind-blown sand movement.The air and sand phases are dissected to single particles.The status of dissected sand grains was consistent with their natural status,so the sand movement can be accurately described.It is very simple and accurate to deal with the collision role by setting smoothing length.SPH method was firstly applied in the numerical simulation of gas-solid two-phase flow in this paper.In this study,the numerical simulation of wind-blown sand movement near the ground surface was performed to observe the micro-scale motion of sand,and to reveal the interaction mechanism of air flow and sand.

Key words: wind-blown sand movement, smoothed particle hydrodynamic method, sand grain velocity, probability density