CFD For Flow Simulation Of Particulate Matter In The Respiratory System

At present,smog has caused a variety of respiratory diseases,and at the same time,drug-targeted inhalation therapy has been developed for the treatment of respiratory diseases.In order to better understand the flow phenomenon of smog particles entering the respiratory system and the effect of drug particle targeted therapy,the paper studied the flow and deposition of particulate matter in the respiratory system.The topic has practical significance.The paper achieved the following results:1.Using computational fluid dynamics(CFD)method combined with respiratory anatomy data to model and simulate the three different geometric shapes of the upper respiratory tract,bronchial tree and alveolar region in the respiratory system,respectively,and obtain the particulate matter in each Part of the flow and sedimentation phenomena and principles;and through the error analysis and comparison with the experimental data and calculation data in the previous literature,the feasibility and authenticity of the established calculation model are verified.2.Based on the verification of the established calculation model,the particles of different particle size values and initial velocity values in the upper respiratory tract,bronchial tree and alveolar region were calculated and compared,and the main deposition locations of the particles in each part were obtained.And the main sediment particle size.1)Upper respiratory tract:The particulate matter is subjected to the initial inertial force.The main sediment is distributed on the upper wall of the upper respiratory tract,the outer side of the pharynx and the inner side of the larynx.The sedimentation is mainly based on the particle size of 5-10 ?m.2)Bronchial tree:Particulate matter is mainly affected by gravity and wall elastic collision.In the 1-4 bronchial tree,the particles are mainly deposited on the bronchial branches and nearby walls,and the sediments are mainly composed of particles with a particle size of 3-5 ?m.In the 5-8 bronchial tree,the particles are deposited more in the right lung and lower lobe.Among them,the upper left and right upper lobe are mainly deposited with 0.1-1 ?m particles,and the left and right upper lobe are lower and lower left.The branch was mainly composed of 4 ?m particles,and the lower left branch,the right middle lobe and the lower right lobe were mainly deposited with 5 ?m particles.3)Alveolar area:The particulate matter is mainly deposited by the flow of airflow in the inner side of the alveoli in a cyclic motion,mainly composed of 0.1-1?m particles.