Water Vapor Transport and Its Effects on the Deposition of Hygroscopic Droplets in a Human Upper Airway Model

Figures & data

FIG. 1 3-D views of the oral airway model and bifurcation airway model (generations G0 to G3). B1—first bifurcation, B2.1 and B2.2—second bifurcation, B3.1, B3.2, B3.3, and B3.4—third bifurcation (the dashed lines indicate the segmental boundaries).

FIG. 2 Comparison of diameter and temperature evolution for a water droplet with the experimental data of Smolik et al. (2001).

FIG. 3 Mean air temperatures in the present simulation compared with experimental values of McFadden et al. (1985) and calculated results of Daviskas et al. (1990) with T_in = 26.7°C and Q_in = 30 l/min.

FIG. 4 Variations of cross-sectional averaged relative humidity with Q_in = 30 l/min in: (a) the oral airway model; and (b) the bifurcation airway model G0–G3.

FIG. 5 Effects of inlet relative humidity and air temperature on the mass transfer coefficient of water vapor (Q_in = 30 l/min).

FIG. 6 Regional Sherwood number (Sh) versus the product of Re and Sc for the human upper airway model.

FIG. 7 Variations of evaporation rate of isotonic saline droplets in the oral airway model under different inhalation conditions: Influence of (a) inhalation flow rate; (b) inlet RH and high T_in; and (c) inlet RH and low T_in.

FIG. 8 Trajectories and diameter evolution of selected isotonic saline droplets in the oral airway model with Q_in = 30 l/min, T_in = 303 K and RH_in = 60%.

FIG. 9 Evaporation rate of isotonic saline droplets in the bifurcation airway model G0-G3 under different inhalation conditions: Influence of (a) inlet RH, initial particle size and high T_in; and (b) initial particle size and inlet air temperature.

FIG. 10 Cumulative distribution of isotonic saline droplet sizes at the inlet of the bifurcation airway model: Influence of (a) inhalation flow rate; (b) inlet RH and high T_in; and (c) inlet RH and low T_in.

FIG. 11 3-D distributions of deposition enhancement factor (DEF) in the oral airway model for micro-size isotonic saline droplets.

FIG. 12 3-D distributions of deposition enhancement factor (DEF) in the airways G0 to G3 for micro-size isotonic saline droplets.

Smolik , J. , Dzumbova , L. , Schwarz , J. and Kulmala , M. 2001 . Evaporation of Ventilated Water Droplet: Connection between Heat and Mass Transfer . J. Aerosol Sci. , 32 : 739 – 748 . [CROSSREF] [CSA]

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