Combined bimodal and dense-sparse structures to optimize the performance of fibrous media for submicron particle capture

Fibrous media are widely used in particle filtration. However, few studies have investigated the performance of fibrous media with bimodal and dense-sparse structures. In this study, computational fluid dynamics technology was adopted to simulate the filtration performance of fibrous media. A two-dimensional random multifiber distribution model was proposed based on VC++ and ICEM. Reliability was verified by comparing the model with the empirical formula. The filtration efficiencies and quality factors of submicron particle capture within different fiber arrangements, inlet velocities, and particle diameters were determined. Finally, the mechanism for improving the filtration efficiency of multi-fiber for submicron particles was analyzed. The results showed that, as the particle diameter and inlet velocity increased, the filtration efficiency and quality factor of the different fibrous media decreased, and tended to be similar. The fibrous media combined with bimodal and dense-sparse structures had the highest quality factor owing to the placement of the bimodal structure on the windward side and ratio of coarse to fine fibers.