Abstract:The flow field around the open storage piles behind a porous fence was numerically simulated by the software Fluent 6.3. The critical porosity was determined based on the datas obtained from the simulation of flow fields for the porous fence with different porosities and the shear stress distribution above the windward side, flat top surface and leeward side of the pile. As a result, the flow structures at high porosities (0.3,0.4,0.6) were similar to that of the unfenced condition. The air velocity was higher from the ground to the top of the windward surface and the velocities were all positive. At low porosities (0,0.2), however, the flow structure differed strongly with that of the high porosities. Large-scale vortices were formed between the fence and the storage pile, thus the velocity of the air above the windward was negative. For the fence with e=0, the height of vortex center was higher 3m than the height of the pile and for the fence with e=0.2, the vortex center located at the 2/3 height of the windward surface. In addition, the shear stress distribution was similar to that of the unfenced condition when the fence porosity was exceeded 0.3and the shear stress increased with the increasing porosities. For the e=0.2 porous fence, however, as the height of the pile increased, the shear stress increased, then decreased and the maximum shear stress was at the 3/5height of the pile. When the fence porosity was 0.25, both vortex and attached flow were formed above the windward surface and the shear stress of the pile was to be the least. Thus the porosity e=0.25 below or above which turbulence structures and the shear stress distributions differed strongly was determined to be the critical porosity in this study. The method studying aerodynamics microscopic characteristics around the piles provides a new idea for the porous fence investigation.
潘武轩, 何鸿展, 宋翀芳, 李临平. 露天堆场防风抑尘网临界孔隙率的数值模拟[J]. 中国环境科学, 2015, 35(6): 1638-1644.
PAN Wu-Xuan, HE Hong-Zhan, SONG Chong-Fang, LI Lin-Ping. Numerical simulation for critical porosity of porous fences used to shelter open storage piles. CHINA ENVIRONMENTAL SCIENCECE, 2015, 35(6): 1638-1644.