Numerical Simulation Of Inhalational Particle Deposition In Human Trachea

In recent years, air pollution is much more serious. Human body health has beenendangered. Among all the air pollution, the suspended particulate matter in theatmosphere is the main factor of atmosphere pollution. Also it is the arch-criminal thatcauses human kinds of respiratory disease. These suspended particulate has verycomplicated composition. It is formed after the various kinds of dust, smoke, and tailgases’ mingle, combine chemical reactions with each other. And it has surface adsorptioneffect of toxic and even carcinogenic substances. This not only affects climate and airquality but also destroy the ecological environment and historical relics. Even more itcauses serious damage to the human respiratory system. Therefore, it is great significanceto research the movement and deposition mechanism of particulate matter in the humanrespiratory apparatus. The research could not only find the basis of some respiratorydiseases in pathology, but also can provide some new directions for pharmaceuticalscience research at the same time.About the simulation studies of particulate matter’s deposition in the trachea, mostpresent researches are based on Weibel’s lung model A. This study reconstructs a realhuman trachea model utilizing the CT scan image of medicine. At the same time the RNG-model was adopted for simulating of flow field which can handle high curvaturestreamline better. And for the solid phase-particles, we use stochastic trajectories ofLagrangian to simulate the particle’s moving trajectory.In order to understand the influence to the particle deposition in the trachea when wechange the respiration intensity, particle size and tube shape, and this paper established atrachea model of three different pipe shape: straight tube model, the bending tube modeland Y-tube model. Also, each model we studied four kinds of respiratory intensity include15L/min,30L/min45L/min and60L/min, and five particle sizes include0.1μm,0.25μm,1μm,0.5μm, and2.5μm respectively. Results show that when the particle size smaller than2.5μm, the particle deposition efficiency has bigger relations with the shape of the particle and the respiratory intensity. But the effect of the particle size to the deposition is notobvious.