3D Numerical Simulation Of Porous Fence And Study On Law Of Dust Dispersion

The wind erosion could cause dusting in the open storage area at the harbor. The dust particles in the air diffuses far in the air, which causes severe air pollution. The porous fence, as a new method of anti-pollution measures, has a great effect in diminishing the wind speed and dusting. At the mean time, porous fence is ecological, economical and social. So the further study of the mechanism of diminishing of wind speed and dusting of porous fence is necessary, which would greatly promote the engineering design and application.Based on the previous research, this paper aims to simulate the wind flow of the porous fence with different porosity and section with the help of a CFD software-FLUENT in order to conduct further study of the sheltering effect of the non-planar porous fence. This paper analyzes the wind flow of each fence in detail. At the same time, average wind diminishing ratio is proposed to evaluate the porous fence. Through the contrastive analysis of the average wind diminishing ratio and the development of turbulence behind the porous fence, this paper points out that the fence with lower porosity has better performance than the higher ones, but the turbulence intensity is the opposite. The fence with butterfly shaped section has smooth streamline behind it, which contributes lower turbulence intensity. However, the average wind diminishing ratio is slightly worse than the plane shaped ones. Then, another2D simulation is conducted and the result points out that the fence with porosity of20%has the best wind diminishing effect in0h-10h. Finally, the surface pressure, surface wind and surface turbulence intensity of the piles after a porous fence are also analyzed through another simulation, the data of which shows that the porous fence performs excellently in diminishing the dusting of the piles.After the study of the porous fence, this paper also does some work in the study of dust dispersion law. Based upon the Gaussian diffusion model, this paper researches the changes of the diffusion wind speed and the diffusion trajectory of the particles caused by the porous fence. The filter trap mechanism is also used in the analysis of the collisions between the fence and the particles. Based on the above analysis, the new modified diffusion model is applied in forecasting dust concentration on condition of setting porous fence.