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Characterization of the localized hydrodynamic shear forces and dissolved oxygen distribution in sparged bioreactors

Authors

  • Athanas Koynov,

    1. Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, New Jersey
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  • Grétar Tryggvason,

    1. Department of Mechanical Engineering, Worcester Polytechnic Institute, Worcester, Massachusetts
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  • Johannes G. Khinast

    Corresponding author
    1. Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, New Jersey 08845-8058; telephone: 732-445-2970; fax: 732-445-2581
    • Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, New Jersey 08845-8058; telephone: 732-445-2970; fax: 732-445-2581.
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Abstract

Detailed, high-resolution numerical simulations of the bubbly flows, used for oxygen delivery and mixing in mammalian cell suspensions, have been performed. The hydrodynamics, shear and normal forces, mass transfer and mass transport from and around individual bubbles and bubble clusters were resolved for different operating conditions, that is, Weber, Morton, and Schmidt numbers. Suspended animal (e.g., mammalian, insect) cells are known to be susceptible to damage potentially leading to cell death, caused by hydrodynamic stresses and oxygen deprivation. Better knowledge of the magnitude of the shear forces and the extent of mixing of the dissolved oxygen in sparged bioreactors can have a significant impact on their future design and optimization. Therefore, the computed liquid-phase velocity fields were used to calculate and compare the local shear in different types of single bubble wakes and in bubble clusters. Oxygen mass transfer and dissolved oxygen transport were resolved to examine oxygen supply to the cells in the different types of flows. Biotechnol. Bioeng. 2007;97: 317–331. © 2006 Wiley Periodicals, Inc.

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