Browsing by Author "Wu, Jiajun"

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    3D structure design and simulation for efficient particles capture: The influence of nanofiber diameter and distribution
    (Materials Today Communications, 2020) Wu, Jiajun; Akampumuza, Obed; Liu, Penghong; Qin, Xiaohong
    Software simulation is a convenient and efficient way to design and check different air filter structures with high efficiency and low pressure drop. In this work, nanofiber filters of different diameters ranging from 100 to 900 nm were designed to check their influence on filtration efficiency, pressure drop and quality factor (QF). Slip-flow effect of air molecules was considered on the surface of single fiber. Then, filters with different diameter distributions were constructed to study the filtration efficiency discrepancy when the filter thickness and porosity were kept equal. With a rotation of the filters composed of nanofibers of 500 nm in diameter in the computational domain, the filtration efficiency and QF increased steadily. The simulation results were partially verified by electrospun cellulose acetate nanofiber filter, and meanwhile provide with new insights into the filter structure design of high filtration efficiency with low pressure drop.
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    Simulation of Bimodal Fiber Distribution Effect on Transient Accumulation of Particles During Filtration
    (Journal of Shanghai Jiaotong University (Science), 2021) Akampumuza, Obed; Wu, Jiajun; Quan, Zhenzhen; Qin, Xiaohong
    Modeling has become phenomenal in developing new products. In the case of filters, one of the most applied procedures is via the construction of idealized physical computational models bearing close semblance to real filter media. It is upon these that multi-physics tools were applied to analyze the flow of fluid and the resulting typical performance parameters. In this work, two 3D filter membranes were constructed with MATLAB; one had a random distribution of unimodal nanofibers, and the other, a novel modification, formed a bimodal distribution; both of them had similar dimensions and solid volume fractions. A comparison of their performance in a dust-loading environment was made by using computational fluid dynamic-discrete element method (CFD-DEM) coupling technique in STAR-CCM+. It was found that the bimodal nanofiber membrane greatly improved the particle capture efficiency. Whereas this increased the pressure drop, the gain was not too significant. Thus, overall, the results of the figure of merit proved that adopting a bimodal formation improved the filter’s quality.