An Adjustable Triple-Bifurcation Unit Model for Air-Particle Flow Simulations in Human Tracheobronchial Airways

Abstract

A new methodology for a swift and accurate computer simulation of large segments of the human lung airways is presented. Focusing on a representative tracheobronchial (TB) region, i.e., G0–G15, nano- and micron particle transports have been simulated for Qin=30l∕min, employing an experimentally validated computer model. The TB tree was geometrically decomposed into triple-bifurcation units with kinematically adjusted multilevel outlet/inlet conditions. Deposition patterns and maximum concentrations differ greatly between nanoparticles (1⩽dp⩽150nm) and micron particles (1⩽dp⩽10μm), which may relate uniquely to health impacts. In comparison with semi-analytical particle deposition results, it is shown that such simple “lung models” cannot predict local deposition values but can match computer simulation results for the entire TB region within 2.5–26%. The present study revealed that turbulent air-particle flow may propagate to G5 for the assumed inhalation flow rate. Geometry and upstream effects are more pronounced for micron particle deposition than for nanoparticle deposition.