This example simulates mixing of sulphur-hexafloride with nitrogen in a model of the airways. The model uses a symmetric conducting airway system, based on Weibel's model A, down to generation 16. Because the model is symmetric, only a single pathway needs to be considered. Attached to the end of the terminal conducting airway is a multi-branching point model (see modeling work by Paiva et al. for a description) of a single pulmonary acinus, with geometry based on the morphological study of Haefeli- Bleuer and Weibel. The figures below show the respiratory portion of the model at end inspiration and end expiration, with the gas concentration field coloured.
Created by Merryn Howatson Tawhai.
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Concentrations at end of inspiration |
Concentrations at end of expiration |
Sulphur-hexafloride is washed in (red). The concentration front can clearly be seen at the end of inspiration. At the end of expiration there are only small concentration differences in the acinus model.