Kumar Amit, Gautam Sashank, Bhatta Nishant, Tafreshi Hooman V, Pourdeyhimi Behnam
Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, 27606, NC, USA.
The Nonwovens Institute, NC State University, Raleigh, 27606, NC, USA.
Soft Matter. 2025 Jan 2;21(2):198-208. doi: 10.1039/d4sm01105h.
Aerosol filters composed of electrostatically charged bipolar fibers are referred to as electret filters. A novel computational model is developed in this work to study the impact of droplet deposition on aerosol capture efficiency of electret fibers. The electret fibers were assumed to have a dipole orientation that was either parallel or perpendicular to the airflow direction. The simulations were conducted using the ANSYS CFD code after it was enhanced with a series of in-house subroutines. Our simulations revealed that droplet deposition on electret fibers decreases their ability to capture airborne particles. More specifically, the simulations were devised to isolate droplet's physical and electrical properties (, surface tension, electrical conductivity…) and quantify their impact on fiber capture efficiency. It was found, in particular, that droplet's electrical conductivity and permittivity have the most adverse impact on the performance of an electret fiber. This is perhaps because higher droplet conductivity results in severe fiber charge neutralization, and higher droplet permittivity leads to a stronger fiber charge shielding. In contrast, fiber wettability was found to have a negligible impact on fiber efficiency. The work presented in this paper offers valuable insights into the complex nature of electret filters used in different industrial and environmental applications.
由带静电的双极纤维组成的气溶胶过滤器被称为驻极体过滤器。在这项工作中开发了一种新颖的计算模型，以研究液滴沉积对驻极体纤维气溶胶捕获效率的影响。假设驻极体纤维的偶极取向与气流方向平行或垂直。在使用一系列内部子程序对ANSYS CFD代码进行增强后，进行了模拟。我们的模拟表明，驻极体纤维上的液滴沉积会降低其捕获空气中颗粒的能力。更具体地说，模拟旨在分离液滴的物理和电学性质（表面张力、电导率等），并量化它们对纤维捕获效率的影响。特别是发现，液滴的电导率和介电常数对驻极体纤维的性能有最不利的影响。这可能是因为较高的液滴电导率会导致严重的纤维电荷中和，而较高的液滴介电常数会导致更强的纤维电荷屏蔽。相比之下，发现纤维润湿性对纤维效率的影响可以忽略不计。本文所展示的工作为不同工业和环境应用中使用的驻极体过滤器的复杂性质提供了有价值的见解。
