10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
Abstract View
Effects of Airway Surface Roughness on Local Particle Deposition in Subject-Specific Tracheobronchial Trees
YU FENG, Xiaole Chen, Jianan Zhao, Arvind Santhanakrishnan, Oklahoma State University
Abstract Number: 29 Working Group: Aerosol Modeling
Abstract Computational Fluid-Particle Dynamics (CFPD) models are useful are useful and efficient to understand inhaled aerosol dynamics in human respiratory systems. Crucial to such models is the accuracy of predicting particle depositions. Reconstructed from CT/MRI scanned data, subject-specific human airway configurations are widely used in computational lung aerosol dynamics research. Smoothing the airway surfaces is inevitable during this process. However, the smoothing criteria used are inconsistent among research groups, which may lead to errors in particle deposition results. To investigate the roughness effect and enhance the reliability of the CFPD model, this research simulated the transport and deposition of inhaled particles in 3 tracheobronchial trees reconstructed from the same CT data for a healthy subject with different smoothing intensities. The inhalation flow rate ranges from 30 L/min to 120 L/min, and the particle size is from 50 nm to 10 µm. Numerical results indicate that improper smoothing process will underpredict particle deposition fractions up to 50% in the trachea, which is due to the underestimated turbulence fluctuation effect on particle deposition. In contrast, it is interesting to notice that the roughness effect on particle depositions from Generation 2 (G2) to Generation 6 (G6) is negligible. In conclusion, smoothing process has a significant impact on laminar-to-turbulence transition and local turbulence intensity, thereby influencing particle deposition result variations in the trachea. To employ a proper smoothing process to reconstruct the 3D lung airway geometries for in silico studies, it is necessary to accurately measure the airway surface roughness considering the presence of mucus layers. To build a more accurate and realistic in silico model for lung aerosol dynamics research, a generalized and unified guideline of the smoothing procedure will be developed based on the extensive intersubject variability studies among virtual population groups with statistical robustness.