Simulation study on the mass transport in PCL based on the ciliated dynamic system of the respiratory tract

In this paper, a two-dimensional dynamic model of human respiratory cilia is established by immersed boundary-lattice Boltzmann method. In the model, periciliary liquid and mucus layer with different flow characteristics are considered, in which the non-Newtonian fluid in the viscous layer is described by Oldroyd-B model; the area between two layers is dynamically divided by a virtual membrane. By changing the cilium beat amplitude and the depth of periciliary liquid, this paper focuses on the removal of particle impurities by cilium beat. The results show that when the initial position is near the top of cilium, the particle tends to migrate upward to approach the mucus layer. However, if the initial position is near the middle or at lower part of the cilia, most of the particles will not be transferred to the vicinity of mucus layer by the swinging cilium. It is also found that by increasing the beat amplitude of cilia, particles are more likely to approach the mucus layer. By conducting this study, the migration of the particle in periciliary liquid is discussed in detail. The results are significant to help us to know the material transport law of human respiratory tract.