https://doi.org/10.1140/epje/i2011-11054-3
The fluctuation property of blown sand particles and the wind-sand flow evolution studied by numerical method
Key Laboratory of Mechanics on Western Disaster and Environment, Department of Mechanics, LanZhou University, 730000, LanZhou, Gansu, China
* e-mail: xjzheng@lzu.edu.cn
Received:
21
January
2011
Revised:
27
March
2011
Accepted:
11
April
2011
Published online:
30
May
2011
Sand particles blown by wind cause serious environmental problems and many researchers are trying to understand the dynamic properties of blown sand better. But the existing numerical approaches have not been able to simulate many important characteristics of wind-sand flow. In this paper, the evolution and fluctuation properties of blown sand at a dynamic steady state are investigated by using a more effective method. Using the LES (large eddy simulation) method for air phase movement and the DEM (discrete element method) for solid phase movement along with the existing particle-bed splashing function, we have characterized the whole movement property of the wind-sand system. The results indicate that the saturation time decreases with the inlet friction velocity, and it gradually reaches the shortest saturation time of about 1s; the saturation length, which is about 14 m at the usual wind velocity, first increases with wind velocity and then reaches a plateau; within the saturation length, the sand transport rate at different positions varies with time; the sand transport rate of the stable wind-sand flow is non-uniform with distance downwind and time, and has a notable correlation with the inflow friction velocity.
© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg, 2011
