纤维过滤介质渗透率及压力损失数值模拟

Numerical Simulation on permeability and Pressure Drop of Fibrous Filtration Media

针对纤维过滤介质纤维杂乱无章分布的特性,采用计算机模拟生产接近真实过滤介质的随机排列的三维纤维微观结构,对其内部流场进行数值模拟,得出纤维过滤介质内部流场三维压力及速度分布曲线图.通过大量计算及回归分析,获得随机排列纤维过滤介质无因次压降和渗透率拟合关联式.研究结果表明:随着迎面风速的增大,过滤介质压力损失线性增加;过滤介质压降随着填充密度的增大而非线性增加;随机排列纤维过滤介质无因次压降的计算结果与Davies及Jackson的计算结果非常吻合.

The microstructure of the fibrous filtration media has a great influence on the fibrous filtration media filtration performance,three-dimensional microstructure of fibrous filtration media which arranged randomly simulated by computer in this paper,the influence of the fibrous filtration media microstructure on filter permeability and pressure drop were investigated.Dimensionless pressure drop correlation of randomly arranged fibrous filtration media was obtained.By fibrous medium simulation it can be known that fiber flow field distribution was not symmetry because the fibers were arranged randomly,filtration velocity was smaller near the fiber when air flowed through the fibers,the fluid velocity increased significantly between the fibers when the fiber distance between fibers was the large.Obvious vortex was formed in the fiber sparse areas.The results show that： the pressure drop of fibrous filtration media increased linearly with the face filtration velocity increasing;and pressure drop non-linear increased with the packing density increasing,dimensionless pressure drop calculation of randomly arranged fibrous filtration media was good agreement with the calculated results of Davies and Jackson.