A study on mucus flow in human lung airways

Abstract

In this paper, a planar two-layer steady state mathematical model is presented to study mucus flow in human lung airways due to cilia beating and some immotile cilia forming porous matrix bed in serous sublayer in contact with epithelium. The effect of air-motion is considered by prescribing the shear stress at the mucus-air interface. The effects of pressure drop and gravitational force are also considered in the model. It is shown the mucus flow rate increases as the pressure drop or gravitational force increases. It also increases as the shear stress generated due to air-motion or porosity parameter increases whereas it decreases as the viscosity of the serous layer fluid or that of mucus increases. It is also shown that the increase in mucus viscosity at higher values do not have any significant effect on its flow rate. It is also found that for a fixed total thickness of mucus and serous layer, there exists a serious fluid layer thickness for which mucus flow rate is maximum.