Committee Chair

Ranjan, Reetesh

Committee Member

Sreenivas, Kidambi; Margraves, Charles

Department

Dept. of Mechanical Engineering

College

College of Engineering and Computer Science

Publisher

University of Tennessee at Chattanooga

Place of Publication

Chattanooga (Tenn.)

Abstract

This study employs a large-eddy simulation (LES) strategy to investigate airflow and aerosol dynamics in the human upper airways using a truncated SimInhale configuration. Inflow conditions include three steady inhalation flow rates (14.2, 53.2, and 71 L/min), representing quasi-laminar, moderate, and high turbulence conditions, and a realistic cyclic breathing scenario. Under steady flow, monodisperse (1–10 μm) and polydisperse aerosols are analyzed. The study shows that complex airflow dynamics directly influence aerosol transport and deposition, causing global deposition to increase nonlinearly with particle size and Reynolds number, with the larynx being a primary deposition location in turbulent cases. For the polydisperse analysis using uniform, Gaussian, and Rosin-Rammler distributions, the Rosin-Rammler yielded the lowest deposition, while the uniform had the highest. Simulation of the realistic breathing cycle with monodisperse particles shows that deposition occurs almost entirely during the inspiratory phase, with the expiratory phase acting as a clearance mechanism.

Acknowledgments

I would like to acknowledge my advisor, Dr. Reetesh Ranjan, for his instrumental mentorship, guidance, and support throughout this research. I would also like to thank Dr. Charles Margraves and Dr. Kidambi Sreenivas for serving on my thesis committee and for their valuable time and feedback. I am also grateful to the Fluid and Combustion Modeling Group for their support and collaboration. I also acknowledge the National Science Foundation (Grant #2324691) and the Department of Mechanical Engineering at the University of Tennessee Chattanooga (UTC) for supporting this research. Lastly, I thank the UTC Research Institute for providing all the high-performance computing resources to carry out the simulations in this work.

Degree

M. S.; A thesis submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Master of Science.

Date

5-2026

Subject

Aerosols--Physiological transport; Air flow--Mathematical models; Respiratory organs--Simulation methods

Keyword

Human upper airways; airflow; aerosol transport and deposition; Eulerian-Lagrangian formulation; large-eddy simulation

Document Type

Masters theses

DCMI Type

Text

Extent

xv, 113 leaves

Language

English

Rights

http://rightsstatements.org/vocab/InC/1.0/

License

http://creativecommons.org/licenses/by/4.0/

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