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LES & DES study of Fluid-Particle Dynamics In Human UpperRespiratory Pathway

Boekbijdrage - Boekhoofdstuk Conferentiebijdrage

Inhaled medication is generally the preferred method of drug administration to the lung for the first-line
therapy of asthma and chronic obstructive pulmonary diseases. For an efficient treatment, the inhaled
aerosol particles need to bypass the complex airway morphology and reach the alveolar zone of the
respiratory tract where it eventually gets absorbed. The complexity of extrathoracic pathway which
involves bends, sudden cross-sectional changes, branching bronchi and non-symmetry of the geometry
generally results in major deposition of inhaled medication in the pathway before reaching the lungs. With the upper airway flow being transitional, the use of models two-equation RANS models, which
are basically developed for turbulent flows may always result in poor prediction. Previous
works conclude that the Reynolds Averaged Navier Stokes (RANS) as well as Reynolds Stress
Model (RSM) does not capture relevant features of the flow and highlighted the need to switch towards
Large Eddy Simulation (LES). To have a complete overview of available numerical methods, all the
modeling methods, namely the Reynolds Averaged Navier Stokes (RANS), Detached Eddy Simulation
(DES) and Large Eddy Simulation (LES) are tested in the present work. In case of RANS, the best
performing SST k - omega turbulence model is employed. DES is based on Spalart-Allmaras model for
the near-wall region. In case of LES, two subgrid scale models, namely the Smagorinsky-Lilly and the
WALE model were tested. The particle phase is computed in truly unsteady mode, both for DES and
LES. The frozen LES method is also tested. All the results were compared with the
experimental data to analyze their reliability.
Boek: ECCOMAS
Jaar van publicatie:2008
Trefwoorden:Large Eddy Simulation, Detached Eddy Simulation, Upper Respiratory Pathway, Aerosol Deposition
  • ORCID: /0000-0003-0231-2756/work/64643212