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@ARTICLE{Rttgers:1048915,
      author       = {Rüttgers, Mario and Vorspohl, Julian and Mayolle, Luca and
                      Johanning-Meiners, Benedikt and Krug, Dominik and Klaas,
                      Michael and Meinke, Matthias and Lee, Sangseung and
                      Schröder, Wolfgang and Lintermann, Andreas},
      title        = {{C}omparative analysis of the flow in a realistic human
                      airway},
      journal      = {Physics of fluids},
      volume       = {37},
      number       = {12},
      issn         = {1527-2435},
      address      = {[Erscheinungsort nicht ermittelbar]},
      publisher    = {American Institute of Physics},
      reportid     = {FZJ-2025-05014},
      pages        = {121901},
      year         = {2025},
      abstract     = {Accurate simulations of the flow in the human airway are
                      essential for advancing diagnostic methods. Many existing
                      computational studies rely on simplified geometries or
                      turbulence models, limiting their simulation’s ability to
                      resolve flow features such as shear-layer instabilities or
                      secondary vortices. In this study, direct numerical
                      simulations were performed for inspiratory flow through a
                      detailed airway model that covers the nasal mask region to
                      the sixth bronchial bifurcation. Simulations were conducted
                      at two physiologically relevant REYNOLDS numbers with
                      respect to the pharyngeal diameter, i.e., at $Re_p$ = 400
                      (resting) and $Re_p$ = 1200 (elevated breathing). A
                      lattice-Boltzmann method was employed to directly simulate
                      the flow, i.e., no turbulence model was used. The flow field
                      was examined across four anatomical regions: (1) the nasal
                      cavity, (2) the naso- and oropharynx, (3) the laryngopharynx
                      and larynx, and (4) the trachea and carinal bifurcation. The
                      total pressure loss increased from 9.76 Pa at $Re_p$ = 400
                      to 41.93 Pa at $Re_p$ = 1200. The nasal cavity accounted for
                      the majority of this loss for both vortices in the
                      nasopharyngeal bend and turbulent shear layers in the
                      glottis jet enhanced the local pressure losses. In contrast,
                      the carinal REYNOLDS numbers, though its relative
                      contribution decreased from $81.3\%$ at $Re_p$ = 400 to
                      $73.4\%$ at $Re_p$ = 1200. At $Re_p$ = 1200, secondary
                      bifurcation mitigated upstream unsteadiness and stabilized
                      the flow. A key outcome is the spatial correlation between
                      the pressure loss and the onset of flow instabilities across
                      the four regions. This yields a novel perspective on how the
                      flow resistance and vortex dynamics vary with geometric
                      changes and flow rate.},
      cin          = {JSC},
      ddc          = {530},
      cid          = {I:(DE-Juel1)JSC-20090406},
      pnm          = {5111 - Domain-Specific Simulation $\&$ Data Life Cycle Labs
                      (SDLs) and Research Groups (POF4-511) / HANAMI - Hpc
                      AlliaNce for Applications and supercoMputing Innovation: the
                      Europe - Japan collaboration (101136269)},
      pid          = {G:(DE-HGF)POF4-5111 / G:(EU-Grant)101136269},
      typ          = {PUB:(DE-HGF)16},
      doi          = {10.1063/5.0301891},
      url          = {https://juser.fz-juelich.de/record/1048915},
}