Numerical calculation and analysis of filtration performance of an effective novel structural fiber for PM2.5

In this study, a novel fiber with slit-crescent-shaped cross-section is proposed to enhance the filtration performance of PM2.5 in fibrous filtration. The collection efficiency of this fiber is simulated by using a Brownian dynamics simulation technique, and its filtration pressure drop is obtained by numerically solving Navier-Stokes equation with Fluent software. A parametric study is performed to improve the optimum filtration performance of the slit-crescent-shaped fiber via adjusting its structural parameters (dimensionless center-to-center spacing and slit width). Results indicate that at the optimal condition, i.e., when dimensionless slit width ranges from 0.2 to 0.4, collection efficiency is enhanced by 13.1%-101.1% relative to the circular fiber for particles ranging from 0.1μm to 2.5μm for the slit-crescent-shaped fiber under various dimensionless center-to-center spacing, and filtration pressure drop is reduced by up to 14.4%. In addition, quality factor is introduced to evaluate the comprehensive filtration performance of the slit-crescent-shaped fiber with different structural parameters, and results show that large dimensionless slit width and small dimensionless center-to-center spacing lead to a much higher quality factor than the circular fiber, especially for particles lager than 0.5μm. The numerical results obtained in this work are conducive to designing high efficiency fibrous filters.