Version 1
: Received: 6 January 2023 / Approved: 10 January 2023 / Online: 10 January 2023 (11:47:47 CET)
Version 2
: Received: 3 February 2023 / Approved: 6 February 2023 / Online: 6 February 2023 (10:04:47 CET)
Espinosa-Moreno, A.S.; Duque-Daza, C.A.; Garzón-Alvarado, D.A. Influence of Morphological Parameters on the Flow Development within Human Airways. Fluids2023, 8, 78.
Espinosa-Moreno, A.S.; Duque-Daza, C.A.; Garzón-Alvarado, D.A. Influence of Morphological Parameters on the Flow Development within Human Airways. Fluids 2023, 8, 78.
Espinosa-Moreno, A.S.; Duque-Daza, C.A.; Garzón-Alvarado, D.A. Influence of Morphological Parameters on the Flow Development within Human Airways. Fluids2023, 8, 78.
Espinosa-Moreno, A.S.; Duque-Daza, C.A.; Garzón-Alvarado, D.A. Influence of Morphological Parameters on the Flow Development within Human Airways. Fluids 2023, 8, 78.
Abstract
Anatomical airways parameters as length, diameter and angles have a strong effect on the flow dynamics. Aiming to explore the effect of variations of the bifurcation angle (BA) and carina rounding radius (CRR) of lower human airways on the respiratory processes, numerical simulations of airflow during inhalation and exhalation were performed using a synthetic bifurcation models. Geometries for the airways models were parameterized based on a set of different BA's and several CRR's. A range of Reynolds numbers (\Reyn) relevant to the human breathing process were selected to analyzed the airflow behaviour. The numerical results show a significant influence of BA and the CRR on the development of the airflow within the airways, and therefore affecting some relevant features of the flow, namely the deformation of velocity profiles, alterations of pressure drop, the flow patterns, and finally enhance or attenuation of wall shear stresses (WSS) appearing during the regular respiratory process. Numerical results show that increases in the bifurcation angle value are accompanied by pressure increases of about 20\%, especially in the regions close to the bifurcation. Similarly, increases in the BA value lead to a reduction in peak shear stresses of up to 70\%. For the ranges of angles and radii explored, an increase in pressure of about 20\% and a reduction in wall shear stress of more than 400\% were obtained by increasing the carina rounding radius. Analysis of the coherent structures and secondary flow patterns also revealed a direct relationship between the location of the vortical structures, the local maxima of the velocity profiles and the local vorticity minima. This relationship was observed for all branches analysed, for both the inhalation and exhalation processes of the respiratory cycle.
Keywords
Synthetic human airways; bifurcation angle; carina rounding radius
Subject
Engineering, Bioengineering
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Received:
6 February 2023
Commenter:
Andres Espinosa Moreno
Commenter's Conflict of Interests:
Author
Comment:
Improvement of some sections (introduction and computational model, mainly). Inclusion of numerical validation and mesh sensitivity. Inclusion of 3D flow structures (coherent structures using the Q criterion).
Commenter: Andres Espinosa Moreno
Commenter's Conflict of Interests: Author