Numerical Investigation of the Flow Characteristics Considering the Human Workloads in a Human Airway

Abstract:

The flow characteristicscan be sensitively changed by the respiration flow rate due to the complex geometries, e.g., bends, constrictions in a human airway. Also, caused by the switching the flow direction, the disturbance destabilizes the flow when a human breathes. Thus, the real breathing conditions, e.g., peak flow rate and the breath cycle time related to workload, should be considered to investigate on the flow characteristics in a human airway. In this study, realated to the human workloads, the effect of the change of the respiratory flow rate on the flow characteristics is investigated with the numerical method at the 4-specific normalized times in a breath cycle. In almost time of a breath cycle, as the workload increases, the flow recirculation zone decreases slightly because the energy transport toward the wall increases due to the turbulence fluctuation and the secondary motion.However, when the flow acclecrates in the expiratory phase, the flow recirculation zone increases because of the unsteady effect and the glottal jet. Thus, respiratory flow rate considering the human workloads and the unsteady effect caused by the real respiration should be considered to investigate the flow characteristics and the particle movement in a human airway.

• Periodical: Advanced Materials Research (Volume 647)
• Pages: 487-493
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.647.487
• Online since: January 2013
• Authors: Kun Hyuk Sung, Hong Sun Ryou
• Keywords: Computational Fluid Dynamics (CFD), Human Airway, Recirculation Zone, Secondary Flow Intensity, Turbulence Kinetic Energy

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