A Numerical Simulation of Inspiratory Airflow in Human Airways during Exercise at Sea Level and ...

At high altitudes, the air pressure is much lower than it is at sea level and contains fewer oxygen molecules and less oxygen is taken at each breath. This requires more deep and rapid breathing to get the same amount of oxygen into the blood stream as breathing in air at sea level. Exercises increase oxygen demand and make breathing more difficult at high altitude. In this study, we performed a numerical simulation of inspiratory airflow in a three-dimensional bifurcating human airways model (third to sixth generation) during exercise at sea level and at high altitude. The computational fluid dynamics (CFD) solver FLUENT is used to solve the governing equations for unsteady airflow in the model. Flow velocity, pressure and wall shear stress were obtained from the simulations with the two breathing conditions. The result of this study quantitatively showed that performing exercise with a given work rate at high altitude increases inspiratory airflow velocity, pressure and wall shear stress more than at sea level in the airway model. The ranges of the airflow fields are also higher at high altitude than at sea level. The simulation results show that there no significant differences in flowing pattern for the two breathing conditions.