Constructal Pathway of Particle Dispersion in Children’s Respiratory Dynamics

Abstract

In this work, Constructal Design maximizes access to aerosol particles incorporated into the respiratory airflow flowing along a dichotomous structure with three levels of branching. The objective is to determine the combination of particle size and density that provides the best deposition performance, under size constraints, in three-dimensional (3D) networks with a homothetic relationship between the diameters of the parent and daughter ducts according to the Hess-Murray Law. CFD simulations reproduced the inhalation and exhalation movements under a quasi-sinusoidal pulsed flow. Our results confirm that particle size is the primary factor governing deposition efficiency. Critically, deposition efficiency in the children model is found to be 6% to 11% lower than in comparable adult models from the literature, suggesting deeper particle penetration into children’s lungs. These findings are significant for optimizing aerosolized drug delivery and assessing health risks from airborne pollutants in young children.