Design of a numerical model of lung by means of a special boundary condition in the truncated branches.
The need for a better understanding of pulmonary diseases has led to increased interest in the development of realistic computational models of the human lung.



To minimize computational cost, a reduced geometry model is used for a model lung airway geometry up to generation 16. Truncated airway branches require physiologically realistic boundary conditions to accurately represent the effect of the removed airway sections. A user-defined function has been developed, which applies velocities mapped from similar locations in fully resolved airway sections. The methodology can be applied in any general purpose computational fluid dynamics code, with the only limitation that the lung model must be symmetrical in each truncated branch.



Unsteady simulations have been performed to verify the operation of the model. The test case simulates a spirometry because the lung is obliged to rapidly perform both inspiration and expiration. Once the simulation was completed, the obtained pressure in the lower level of the lung was used as a boundary condition. The output velocity, which is a numerical spirometry, was compared with the experimental spirometry for validation purposes.



This model can be applied for a wide range of patient-specific resolution levels. If the upper airway generations have been constructed from a computed tomography scan, it would be possible to quickly obtain a complete reconstruction of the lung specific to a specific person, which would allow individualized therapies.
University of Oviedo. Hospital Universitario Central de Asturias (HUCA), Avda de Roma s/n, 33011, Oviedo, Spain.
Ana F
AF
Tena
University of Oviedo, Department of Energy, Campus de Barredo, 33600, Mieres, Spain.
Joaquín
0000-0003-1495-9848
J
Fernández
University of Oviedo, Department of Energy, Campus de Barredo, 33600, Mieres, Spain.
Eduardo
E
Álvarez
University of Oviedo. Hospital Universitario Central de Asturias (HUCA), Avda de Roma s/n, 33011, Oviedo, Spain.
Pere
P
Casan
University of Oklahoma, School of Aerospace and Mechanical Engineering, Norman, OK, 73019, USA.
D Keith
DK
Walters
D003198:Computer Simulation; D006801:Humans; D057446:Hydrodynamics; D008168:Lung / Q000033:anatomy & histology* / Q000502:physiology* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed
CFD; boundary condition; truncated branches; user-defined function; velocity mapping technique