Computational fluid dynamics investigation of human aspiration in low-velocity air: Orientation effects on mouth-breathing simulations

T. Renée Anthony, Kimberly R. Anderson

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


Computational fluid dynamics was used to investigate particle aspiration efficiency in low-moving air typical of occupational settings (0.1-0.4 m s -1). Fluid flow surrounding an inhaling humanoid form and particle trajectories traveling into the mouth were simulated for seven discrete orientations relative to the oncoming wind (0°, 15°, 30°, 60°, 90°, 135° and 180°). Three continuous inhalation velocities (1.81, 4.33, and 12.11 m s-1), representing the mean inhalation velocity associated with sinusoidal at-rest, moderate, and heavy breathing (7.5, 20.8, and 50.3 l min-1, respectively) were simulated. These simulations identified a decrease in aspiration efficiency below the inhalable particulate mass (IPM) criterion of 0.5 for large particles, with no aspiration of particles 100 m and larger for at-rest breathing and no aspiration of particles 116 m for moderate breathing, over all freestream velocities and orientations relative to the wind. For particles smaller than 100 m, orientation-averaged aspiration efficiency exceeded the IPM criterion, with increased aspiration efficiency as freestream velocity decreased. Variability in aspiration efficiencies between velocities was low for small (<22 m) particles, but increased with increasing particle size over the range of conditions studied. Orientation-averaged simulation estimates of aspiration efficiency agree with the linear form of the proposed linear low-velocity inhalable convention through 100 m, based on laboratory studies using human mannequins.

Original languageEnglish (US)
Pages (from-to)740-757
Number of pages18
JournalAnnals of Occupational Hygiene
Issue number6
StatePublished - Jul 2013


  • CFD inhalability
  • aspiration efficiency
  • computational fluid dynamics
  • continuous inhalation
  • inhalable particulate mass
  • mouth breathing
  • orientation averaged
  • particle aspiration
  • particle transport
  • ultralow velocity


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