Numerical Simulation of Particles Deposition in a Human Upper Airway

Abstract

Based on the CT scanned images, a realistic geometric model from nasal cavity to upper six-generation bronchia is rebuilt. In order to effectively simulate the particle movement and deposition, LES model is used and the particles are tracked in the frame of Lagrange. Seven kinds of typical particles, including micron particles (1, 5, and 10 m) and nanoparticles (1, 5, 20, and 100 nm), and three representative respiratory intensities are adopted as computational case, respectively. Deposition efficiency ( ), deposition concentration ( ), and capture efficiency ( ) are introduced. Furthermore, the locations of particle deposition are visualized. The results indicate that the injecting particles from different nasal inlet present "transposition effect. " The values of micron particles are much higher than nanoparticles. The particle diameter plays a weaker role in nanoparticle depositions than micron particles. The highest values of and both occur in nasal cavity, while the highest up to 99.5% occurs in bronchus region.

SARS-CoV-2 droplet deposition path and its effects on the human upper airway in the oral inhalation

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“…In this way, airborne particles during inhalation with the small amount of fraction deposition on the airway surfaces can penetrate different parts of the respiratory tract, and thus a variety of beneficial or hazardous substances can enter the body. Li et al [27] findings indicate that the efficacy of micro-particle deposition is much higher than that of nanoparticles. The diameter of nanoparticles is less critical than that of micro-particles in the deposition.…”

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