Transport and deposition of angular fibers in turbulent channel flows

Details

• Personal Author:
  Ahmadi G ; Asgharian B ; Zhang H
• Description:
  Transport and deposition of angular fibrous particles in turbulent channel flows were studied. The instantaneous fluid velocity field was generated by the direct numerical simulation (DNS) of the Navier-Stokes equation via a pseudo-spectral method. An angular fibers was assumed to consist of two elongated ellipsoids attached at their tips. For a dilute suspension of fibers, a one-way coupling assumption was used in that the flow carries the fibers, but the coupling effect of the fiber on the flow was neglected. The particle equations of motion used included the hydrodynamic forces and torques, the shear-induced lift and the gravitational forces. The hydrodynamic interactions of the high aspect ratio linkage were assumed to be negligibly small. Euler's four parameters (quaternions) were used for describing the time evolution of fiber orientations. Ensembles of fiber trajectories and orientations in turbulent channel flows were generated and statistically analyzed. The results were compared with those for spherical particles and straight fibers and their differences were discussed. Effects of fiber size, aspect ratio, fiber angle, turbulence near wall eddies, and various forces were studied. The DNS predictions were compared with experimental data for straight fibers and a proposed empirical equation model. [Description provided by NIOSH]
• Subjects:
  Aerosols Air Pollutants, Occupational Asbestos Chemistry Computers Dust Environmental Monitoring Inhalation Exposure Inorganic Chemicals Occupational Health Particulate Matter Risk Assessment Risk Factors Safety Software

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• Keywords:
  Aerosol-particles Air-sampling Airborne-fibers Analytical-processes Asbestos-dust Asbestos-fibers Chemical-reactions Computer-models Computer-software Exposure-levels Fibrous-dusts Inhalants Models Particulates Risk-factors Sampling

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• ISSN:
  0278-6826
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  New Mexico ; New York ; North Carolina ; OSHA Region 2 ; OSHA Region 4 ; OSHA Region 6
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  41
• Issue:
  5
• NIOSHTIC Number:
  nn:20044477
• Citation:
  Aerosol Sci Technol 2007 May; 41(5):529-548
• Contact Point Address:
  Goodarz Ahmadi, Department of Mechanical and Aero Engineering, Clarckson Univeristy, MAE-Box 5725, Potsdam, NY, USA
• Federal Fiscal Year:
  2007
• Performing Organization:
  Lovelace Biomedical & Environmental Research, Albuquerque, New Mexico
• Peer Reviewed:
  True
• Start Date:
  20020901
• Source Full Name:
  Aerosol Science and Technology
• End Date:
  20080831
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:28468b82958b1347d5c53c97508e41970292f890555efd79cea7a8adf80570c4376fcd1f90e09c1291bd808c0651099e87a625b913b74edcb3e72169ffca6530
• Download URL:
  https://stacks.cdc.gov/view/cdc/200167/cdc_200167_DS1.pdf
• File Type:
  [PDF - 4.77 MB ]