基于微观结构的褶式滤芯拟态化模型及其过滤性能的数值模拟

基于随机多层纤维过滤介质算法建立褶式滤芯三维拟态化结构模型，对褶式滤芯内部气-固两相流动进行数值模拟，计算不同运行参数及结构参数下滤芯的压力损失及过滤效率，并与文献计算值进行比较. 结果表明，压力损失随过滤风速增大呈线性增加；随褶尖角增大，压力损失呈先减小后增加，压力损失计算值与文献计算值吻合较好. 褶尖角和过滤风速一定时，过滤效率随粒径增加先减小后增大，在给出的颗粒直径范围内存在最易穿透颗粒直径(MPPS). 不同过滤风速下，当颗粒粒径小于0.5 mm时，扩散作用使过滤效率随过滤风速增加而减小；大于0.5 mm时，惯性作用使其随过滤风速增加而增加；MPPS随风速增加而减小；本计算值与文献计算值趋势一致. 不同褶尖角下，当颗粒粒径小于1 mm时，扩散作用使过滤效率随褶尖角增大而减小；大于1 mm时，惯性作用使其随褶尖角增大而增加.

Modeling of the Pleated Filter Based on Microscopic Structure and Numerical Simulation of Its Filtration Characteristics

In order to achieve optimal control of randomly arranged fibers, an algorithm that generates the stochastic multilayer fibrous medium was presented based on Poisson stochastic linear process. A 3-D mimicry model of the pleated filter was established. The gas-solid two-phase flow characteristics of the pleated filter were simulated using CFD, and its pressure drop and filtration efficiency under different operating conditions were calculated. And the simulated results were compared with those in the literature. The results show that the simulated values of pressure drop agree with those in the literature, and the pressure drop increases linearly with the filtration velocity, moreover, it decreases firstly and then increases with the pleated corner angle. The filtration efficiency first decreases and then increases with the particle size at the same filtration velocity, and the most penetration particle size (MPPS) exists in the given particle size range. When the particle size is less than 0.5 mm, the filtration efficiency decreases with the filtration velocity. But, when it is over 0.5 mm, the efficiency increases with the velocity. The results also show that MPPS decreases with the filtration velocity. The simulated values of filtration efficiency are consistent with those in the literature. And the filtration efficiency decreases with the filtration velocity when the particle size is less than 1 mm. However, when it is over 1 mm, the efficiency increases with the velocity.