(304f) Modeling Charged Aerosol Transport in Bifurcated Tubes

The transport characteristics of inertial particles in model bifurcated tubes have received considerable attention, particularly in the context of bronchial airways. In contrast, our understanding of electrostatic influence on particulate transport remains fairly limited. This is especially true for aerosols with broad electrostatic charge distributions, for which the most highly charged particle fraction could exert a profound influence on the overall deposition characteristics. The present study uses numerical tracking of charged inertial particles in a single bifurcation to explore these issues. Physical parameters, including particle size and charge distributions, are obtained experimentally for corona-charged fly-ash powder. The electrical mobility of the charged particle cloud is modeled as arising through coulombic interactions between discrete point charges. This approach is shown to result in a more accurate description of charged aerosol transport than the use of the continuum electric field model. It is also shown that the deposition efficiency of charged particles is significantly enhanced when compared with that of uncharged particles, even though the bulk electrical mobility of the charged particles is two orders of magnitude lower than the characteristic particle drag force. The results are relevant to processes involving the transport of charged particles, such as dry powder conveying and pulmonary drug delivery.