Abstract: A discrete random walk dispersion model is applied to study the trajectory characteristics of jumped sand particles in turbulent air flow in this paper.The law of the height and the length of trajectory change with sand diameter and wind velocity are obtained.With the particle diameter increased,the height,length and impact angle of trajectory increased.It is discovered that turbulent oscillation has greater influence on the trajectory of sand particle with smaller diameter.For sand particles with diameter less than 200 μm the trajectory forms computed from oscillate velocity and average velocity have distinct difference.If particle diameter is smaller than 100 μm the particle suspension phenomenon may occur in wind.

Key words: turbulent flow, sand, trajectory