| Abstract [eng] |
This final project examines recent research on the application of microfibers, nanofibers, and their composites in air filtration systems. Various fibers suitable for composites have been considered, and the complex morphologies of micro- and nano-fiber structures in air filtration are reviewed. Utilizing SolidWorks, three different 3D structures were created from disordered polypropylene filament fibers, each with a length of 1 mm and diameters of 0.3 μm and 3.0 μm. Numerical fluid dynamics analysis and FlowSimulation were employed to analyze the airflow penetration between these filaments and calculate the main parameters. A suitable finite element mesh was generated to accurately simulate the airflow through the fibrous materials, capturing filament roundness, fine details, intersections, and other surfaces. The parameters were manually selected, and the software performed the mesh generation. The computational time ranged from minutes to several hours depending on the structural complexity. Four pieces of computer equipment were utilized for the calculations. The measurements were conducted with a surface velocity of 5.3 cm/s at the input and an atmospheric pressure of 101325 Pa at the output. The analysis focused on external flow with laminar characteristics, while considering gravity effects. The computational domain and finite element mesh were optimized based on the capabilities of the computer equipment, resulting in computation times ranging from a few hours to several dozen or even hundreds of hours. Significant differences in airflow penetration were observed between the microfibers and nanofibers. The microfibers exhibited localized turbulence on their surface, causing flow stagnation in certain areas, while the flow around the nanofibers exhibited a non-slip effect. Contrary to expectations, the pressure loss in this study ranged only from 0.3 to 2.0 Pa. The surface velocity was substantially reduced at the beginning of the filter and then maintained a velocity of 1 to 5 mm/s throughout the computational domain. |
