The distribution of the deposition of inhaled particles/aerosols in the lung is highly important for assessing both the effect of inhaled pollutants and the efficiency of delivery of inhaled drugs, such as those used to treat airway inflammation in asthma. Several particle deposition experiments and computations have shown that deposition is enhanced at airway bifurcation zones, particularly at carinal ridges, relative to contiguous tubular airway segments (e.g. Martonen and Hofmann, 1986; Myojo, 1987; Gordon and Orlicki, 1990). Because the occurrence of adverse health effects of inhaled particles may depend on such localized doses, knowledge of the distribution of particle deposition will allow us to perform more realistic risk analyses.
Detailed flow field and the detailed deposition distribution can be been simulated
using numerical methods. 
However, one of the main shortcomings of the current CFD
simulations is that the influence of the possibly turbulent flow on the particles has
been neglected. It is known that the Reynolds number in light breathing (10 L/min)
varies from 800 in the trachea to about 8000 in the heavy breathing (100 L/min),
therefore flow in trachea is highly likely to be turbulent in the high Re regime.
This project aims to evaluate the influence of the turbulence on particle deposition in a simple model of upper airway. The turbulence flow will be simulated by large eddy simulations (LES) using the commercial package Fluent, and the particle paths will be tracked using a finite element code developed initially by Dr. Nicolleau, which employs kinematic simulation. Kinematic simulation is a recent Lagrangian model and has been proven to be successful for tracing turbulent particle dispersions. By combining these two modern CFD techniques, a more realistic approach to the particle depositions in airways will be provided.
This project is supported by an EPSRC grant, and is in collaboration with Dr. F.Nicolleau at Mechanical Engineering, University of Sheffield.
Move up to Dr. X. Y. Luo