MUCUS TRANSPORT IN THE HUMAN LUNGS: A MATHEMATICAL ANALYSIS

In this paper, a planar two layer fluid model is proposed to study mucus transport in the human lungs under steady state condition due to cilia beating and air-motion by considering mucus as a visco-elastic fluid. The effect of air-motion is considered by prescribing air-velocity at the mucus air interface. It is shown that mucus transport increases as the pressure drop, air velocity due to air-motion and the velocity generated by cilia tips increase. It is also noted that the effect of gravity is similar to that of the pressure drop. It is also observed that mucus transport decreases as the viscosity of serous layer fluid or that of mucus increases, but any increase in mucus viscosity at its larger values does not seem to affect the mucus transport. It is also found that for given total depth of serous layer and mucus layer, there exists a serous fluid layer thickness for which mucus transport is maximum. It is also shown that mucus transport decreases as its elastic modulus increases.