Numerical simulation of micro-particle deposition in a realistic human upper respiratory tract model during transient breathing cycle--颗粒学报PARTICUOLOGY

Huang, J., & Zhang, L. (2011). Numerical simulation of micro-particle deposition in a realistic human upper respiratory tract model during transient breathing cycle. Particuology, 9(4), 424–431. https://doi.org/10.1016/j.partic.2011.02.004

Numerical simulation of micro-particle deposition in a realistic human upper respiratory tract model during transient breathing cycle

Jianhua Huang^a, Lianzhong Zhang^{b c *}

a Jiangsu Xuzhou Construction Machinery Research Institute, XCMG Co., Ltd., Xuzhou 221004, China
b School of Physics, Nankai University, Tianjin 300071, China
c State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi’an 710075, China

10.1016/j.partic.2011.02.004

Volume 9, Issue 4, August 2011, Pages 424-431

Received 17 November 2010, Revised 24 January 2011, Accepted 17 February 2011, Available online 6 June 2011.

E-mail: zhanglz@nankai.edu.cn

Highlights

Abstract

An more reliable human upper respiratory tract model that consisted of an oropharynx and four generations of asymmetric tracheo-bronchial (TB) airways has been constructed to investigate the micro-particle deposition pattern and mass distribution in five lobes under steady inspiratory condition in former work by Huang and Zhang (2011). In the present work, transient airflow patterns and particle deposition during both inspiratory and expiratory processes were numerically simulated in the realistic human upper respiratory tract model with 14 cartilaginous rings (CRs) in the tracheal tube. The present model was validated under steady inspiratory flow rates by comparing current results with the theoretical models and published experimental data. The transient deposition fraction was found to strongly depend on breathing flow rate and particle diameter but slightly on turbulence intensity. Particles were mainly distributed in the high axial speed zones and traveled basically following the secondary flow. “Hot spots” of deposition were found in the lower portion of mouth cavity and posterior wall of pharynx/larynx during inspiration, but transferred to upper portion of mouth and interior wall of pharynx/larynx during expiration. The deposition fraction in the trachea during expiration was found to be much higher than that during inspiration because of the stronger secondary flow.

Graphical abstract

Keywords

Human upper respiratory tract; Transient breathing cycle; Airflow pattern; Micro-particle deposition

文章导读