Numerical Simulation Of Airflow And Inhalable Particle Deposition In Realistic Human Upper Respiratory Tract

Nowadays, atmospheric pollution is one of the most important problems whichthreaten the survival of mankind. Inhalable particles are one of the most importantpollutions. According to particle diameter, the particle which D_p≤10μm call inhalableparticle (PM10). It can enter human respiratory apparatus. The particle whichD_p≤2.5μm call respirable particle (PM2.5). it can enter human lung alveolus.Inhalable particles not only contain great influence to climate and air quality, but alsodamage the ecological environment. Last but not least, inhalable particles seriouslyendanger the human respiratory apparatus and it is one of the most dangerousatmospheric particles which endanger human health.Consequently, it is very theoretical significance to research the airflow andinhalable particles deposition in realistic human upper respiratory tract. Apart fromthe understanding of respiratory disease pathogenesis, it also can guide the choice ofspray strength and particle size.In this thesis, based on CT medical data of a boy at the age of nineteen, medicalfinite element method and reverse engineering technology, a new entirethree-dimensional geometry from nasal cavity, pharynx, larynx, trachea to level 1-6bronchi was reconstruction. To investigating airflow and particle deposition inrealistic human upper respiratory tract, RNG k-εturbulence model was used forsolving the primary flow and particle deposition in three breathing intensity such as15L/min, 30L/min, 60L/min. Eleven kinds of the particles are selected. They aredifferent in diameter as follows: 0.1μm, 0.5μm, 1μm, 2.5μm, 3μm, 3.5μm, 4m, 4.5μm, 5μm, 6.5μm and 8μm. The airflow and inhalable particles depositionin realistic human upper respiratory tract was researched with respiratory intensityand particle size changing. In addition, Rosin-Rammler distribution is used forsimulating the mass distribution of inhalable particles in reality. With respiratory intensity and particle size changing, the inhalable particles deposition rate wasanalyzed, and the scope of different size particles deposition rate in the differentposition of upper respiratory tract was summarized.