A Cylindrical Model for Muco-Ciliary Transport in the Human Trachea: Effects of Mucus-Visco Elasiticity and Porosity

A Cylindrical two layer fluid model for the transport of serous and mucus layer in the human trachea and the steady state condition due to cilia beating, some immotile cilia forming porous bed in serous sub -layer in contact with the epithelium and air motion by considering mucus as a visco-elastic fluid are studied. The effect of air-motion due to forced expiration and other processes is considered by prescribing shear stress at mucus air interface. It is shown that the transport of mucus increases as the pressure drop, the velocity generated by cilia tips and porosity parameter increase. It is noted that the effect of gravity is similar to that of the pressure drop. It is observed that the transport of mucus decreases as the viscosity of serous layer fluid or mucus increases, but any increase in mucus viscosity at its higher 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.