2013 journal article

Analysis of non-spherical particle transport in complex internal shear flows

PHYSICS OF FLUIDS, 25(9).

co-author countries: United States of America 🇺🇸
Source: Web Of Science
Added: August 6, 2018

Focusing on ellipsoidal particles of different aspect ratios, the motion characteristics, including critical angle and stable vs. unstable rotational periods, are computationally analyzed in developing and fully developed tubular flows. As an application of particle transport and deposition, the one-way coupled Euler-Lagrange method enhanced by Euler's rotation equations is then employed to simulate laminar-turbulent flow in a subject-specific lung-airway model. First, to gain some basic insight into the dynamics of non-spherical particles, tubular flow is considered where the trajectories of ellipsoidal fibers with randomly initialized incidence angles were released at different inlet-plane positions, computed and visualized. Local and overall particle deposition results are compared between spheres, ellipsoidal fibers, and sphere-equivalent particles for which a revised Stokes diameter was developed. Concerning non-spherical particle transport and deposition in a subject-specific respiratory system, the validated computer simulation model provides realistic and accurate particle-deposition results. Specifically, slender non-spherical particles (i.e., those with higher aspect ratios) are potentially more harmful than thicker ones due to their ability to penetrate into deeper lung regions when somewhat aligned with the major flow field. Furthermore, non-spherical particle deposition is enhanced as the breathing rate increases.