Three-dimensional simulation of airflow in the human respiratory system

In the present study, the human respiratory system from the oral duct is numerically studied. The governing equations for the flow are solved using a pressure-based finite volume method and the SIMPLE algorithm is used for velocity-pressure coupling. Also, SST κ-ω turbulence model is used to model the turbulent airflow. The data used is based on the actual information of the human respiratory system. The main objective of this study is to determine the optimal amount of air inflow using different boundary conditions and describe the behavior of each part of real respiratory system. The results show that the increase of velocity is proportional to the increase of volume flow rate and the amount of turbulence in the airflow increases with the increase of velocity fluctuations. For normal breathing mode, the velocity is up to 1.4 m/s. The velocity for the volume flow rate of 10 lit/m is reduced to 0.48 and increased to 4.5 by 120 lit/m. It was found that oral throat behavior is uncertain except in the standard state corresponds to the flow rate of 30 lit/m.