Session: Rising Stars of Mechanical Engineering Celebration & Showcase

Paper Number: 149673

149673 - Multi-Scale Flow Physics Model for Inhaled Transmission in the Upper Respiratory Tract 

The study of airborne transmission of respiratory pathogens constitutes a rapidly expanding field, predominantly focusing on the expulsion regimes of particulates from infected hosts and their dispersion in confined spaces. Largely overlooked has been the fluid physics associated with inhaled transport within the respiratory cavity. It plays a crucial role in directing virus-laden particulates to infection-prone regions along the human upper airway. This project thus aims to derive a comprehensive understanding of inhaled aerial transport of pathogen-bearing particulates across various spatio-temporal scales within anatomically realistic upper airway domains. The work will also delineate the mechanics of respiratory infection onset by integrating fluid dynamics insights with virological and epidemiological parameters. Research techniques and findings will be blended into two educational modules: (i) a mentorship framework for teachers and students at regional Native American high schools, and (ii) a partnership with the on-campus nursing program to disseminate fluid mechanics perspectives on respiratory care. Module (ii) will also help authenticate the physiological realism of the research paradigm, while module (i) will incorporate an innovative fine arts segment showcasing the role of paintings and sketches in science communication.

The overarching goal of this project is to enable flow physics modeling for inhaled transport of pathogenic particulates within the human upper respiratory tract. The intricate cavity morphology, characterized by expansions, contractions, T- and Y-shaped branches, and narrow inter-tissue crevices, results in complex inhaled airflow patterns. The field instabilities can significantly impact the particle trajectories. Knowing the hazardous inhaled particle sizes that preferentially land at the infective tissue sites, hence ferrying the pathogens there, is key for disease spread modeling. The project addresses this knowledge gap through three research goals: (1) integrating Large Eddy Simulation data with reduced-order mathematical modeling to derive a parametric description of small-scale vortex-dominated instability effects within tortuous and branched spaces common in the upper airway; (2) utilizing Lagrangian tracking to computationally simulate mean advective transport of inert particles that physically mimic inhaled pathogen-bearing particulates, followed by analysis of the intra-airway regional deposition trends with scaling arguments and sample experimental validations in 3D-printed anatomical casts with monodisperse aerosol sprays; and (3) combining fluid dynamics inferences with cross-disciplinary inputs on size distribution and embedded virion concentration of the inhaled particulates to evaluate pathogen-specific parameters, namely the infection-triggering viral load (infectious dose) and safe exposure thresholds. Anticipated findings are poised to establish a novel multi-scale approach for mechanics-based modeling of respiratory disease onset. This project is jointly funded by Fluid Dynamics Program and the Established Program to Stimulate Competitive Research (EPSCoR).

Presenting Author: Saikat Basu South Dakota State University

Presenting Author Biography: Dr. Saikat Basu is an Assistant Professor of Mechanical Engineering at South Dakota State University (SDSU) and directs the Biomedical and Bioinspired Fluid Dynamics Lab there. The group works on fluid dynamics of biophysical systems, with respiratory transport modeling and tumor microenvironment flow physics as focus topics. Basu’s scholarly background is in theoretical and computational fluid mechanics. He received his Ph.D. in Engineering Mechanics from Virginia Tech in 2014, followed by postdoctoral stints at OIST (Japan) and at the UNC Chapel Hill School of Medicine. Dr. Basu joined SDSU in 01/2019 and has since received research grants from the NSF and the NIH, including the prestigious NSF CAREER Award in 2024, along with multiple industry-sponsored projects. Basu’s work on intranasal therapeutics, airborne pathogenic transmissions, and bioinspired filtration has been widely reported on national and global media outlets, e.g., New Scientist, USA Today, Newswise, and National Public Radio.

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