Session: Flow Visualization and Regular Poster Session

Paper Number: 170416

170416 - Flow Structures in the Human Trachea – Experiments and Matched Simulations 

Abstract: 

Respiratory flows present a captivating interplay of various fluid dynamics phenomena, such as turbulent flows in intricate geometries, multiphase flow, and flow-structure interactions. Gaining a deep understanding of tracheal flow is crucial for improving the management of respiratory diseases, developing advanced medical devices, and optimizing drug delivery systems. While decades of research have expanded our knowledge, clear guidelines on how specific morphological features of the upper trachea influence these flows remain absent. Achieving this understanding is a crucial first step toward adopting a physics-based approach to the design and modeling of various biomedical and clinical parameters.

This study visualizes airflow in a custom, 1:1 scaled model of the human trachea (with rigid walls), inspired by the Weibel model parameters. Mineral oil fog is used as a seed particle, and high-speed photography captures the flow through a section of the trachea extending from the upper trachea to the second-generation bronchi. The goal is to investigate the interaction between the carina (the rigid tissue at the primary bifurcation of the trachea into the left and right bronchi) and various breath patterns, including the strength of inhalation and exhalation. Although the carina defines the openings to the bronchi, the flow is rarely symmetric, as shown in this study. The region of the trachea opposite the carina reveals secondary flow patterns that help explain this asymmetry. The experimental findings are supported by transient Reynolds-Averaged Navier-Stokes simulations, which also provide additional quantitative data on velocity gradients and shear stresses at the tracheal walls and carina. This study is ongoing, with further work extending these findings to more realistic breathing cycles and intubated trachea models.

Presenting Author: Aarthi Sekaran SUNY Polytechnic Institute

Presenting Author Biography: