Evidence of Chaotic Mixing in the Alveolar Region of the Lung
We report an experimental and numerical investigation to study the role of asymmetry in the expansion-contraction of the acinar wall on the particle transport in the acinus. We model the acinar flow feature using a T-section by appropriately matching the dimensionless numbers to that in the acinus of healthy human subjects. We show that asymmetry in the expansion-contraction process (quantified by $ϕ$) is required for chaotic advection. We show the stretch and fold process leading to chaos for a range of $ϕ$ and scaled oscillation frequency $Sr$. We show a regime map in this generalize $ϕ$ and $Sr$ space and show that most mammalian lungs fall at the boundary of chaotic regime.
physics.bio-ph↗