Objective To analyze fluid mechanics characteristics of central airway in healthy adults by using computational fluid dynamics(CFD)technique,and study influence of air flow field on central airway.Methods Four healthy adult chest CT images were selected,which included 2 males and 2 females,aged 26-53 years old with mean age of 37.5 years old;body mass was 48.5-74.0 kg with mean body mass of 60.6 kg.Four chest CT images were imported in DICOM format us-ing Mimics 21 medical image software,and three-dimensional model of the central airway was constructed.The three-di-mensional model was trimmed using Geomagic Studio 12 software.After meshing model by Ansys fluent 19.2 software mesh-ing module,which was imported into Ansys 19.2 software for CFD simulation calculation.The simulations were conducted with the same tidal volume,and the variations of airflow within central airway were dynamically analyzed.Results The CFD was used for numerical simulation on three-dimensional model of central airway constructed based on CT image data.The re-sults showed that the inlet velocity of the airflow was 2.15-4.44 m/s at the same tidal volume.The flow rate of airway gradually decreased from the inlet to the outlet,and the high flow rate area was formed.The maximum flow velocity was 3.25-6.77 m/s,the maximum flow velocity was closed to trachea wall,and airway wall pressure gradually decreased from trachea to bronchus.The absolute value of wall pressure in the area with higher flow velocity was higher.The maximum shear stress of airway wall was 0.888-2.240 Pa,in which the shear stress of airway wall,trachea bifurcation and secondary and tertiary bronchus was rel-atively large,and increased with the diameter decrease of trachea and bronchus.Conclusion It is demonstrated that the flow velocity,wall pressure and wall shear stress of airway are closely related to airway structure,which shows a certain overall spatial distribution and local characteristics by using CFD simulation of central airway model for healthy adults.
central airwaycomputer tomography(CT)three-dimentional reconstructioncomputational fluid dynamics(CFD)adult
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