Professor Hooman Tafreshi in the NC State Department of Mechanical and Aerospace Engineering along with Dr. Behnam Pourdeyhimi, Director of the NC State Nonwovens Institute (NWI) are collaborating to address the need for efficient, sustainable, and affordable aerosol filter manufacturing. Despite its widespread applications, aerosol filtration has remained an empirical trial-and-error-based art in desperate need of a design theory and a generalizable manufacturing methodology. This project is aimed at studying the impact of liquid droplet deposition on the performance of electrostatically charged filters. Through this project, Professors Tafreshi and Pourdeyhimi are developing a computational model to simulate the process of charging a filter.
The project started in January 2024, and since then, the research team has developed an in-house computer program to simulate liquid droplet deposition and redistribution in a fibrous filter. Knowing how liquid droplets reside between the fibers allows them to quantify their negative impact on filter’s performance. In particular, the PIs have developed a CPU-friendly simulation technique, referred to as pore morphology method (PMM), that can predict how liquid distributes in a virtual filter under different operating pressures. Their next step is to incorporate the effects of charge shielding and charge neutralization in their simulations.
With these effects included in the model, the PIs will be able to quantify the changes in the collection efficiency and pressure drop of the filter caused by liquid deposition. The success of this project can help to design and manufacture more resilient facemasks and HVAC filters, and thereby can help to reduce the spread of airborne diseases and help the health and wellbeing of the society.
Similar models will also be developed for hydrocharging and triboelectric charging of nonwovens. NWI has over 60 companies as members of its consortium. NWI will communicate the outcomes of the computational work with these companies to gauge their interest in collaborating on larger investigations involving filter production and testing. The proposed study builds a platform for future investigations toward producing sustainable and efficient filtration media for biopharma processes. Such high-efficiency filters generate less pressure drop as they operate, which results in significant energy savings. The PIs consider the Novo Nordisk Foundation as a potential sponsor for the continuation and eventual implementation of this research. KIETS leverages support from the NWI.