Premium
Model of the mass transport to the surface of animal cells cultured in a rotating bioreactor operated in micro gravity
Author(s) -
RiveraSolorio Ivan,
Kleis Stanley J.
Publication year - 2006
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.20864
Subject(s) - bioreactor , sherwood number , péclet number , mass transfer , diffusion , reynolds number , mechanics , steady state (chemistry) , chemistry , chromatography , materials science , analytical chemistry (journal) , thermodynamics , physics , nusselt number , turbulence , organic chemistry
Abstract A mathematical model is used to investigate the transport of dissolved oxygen from the bulk fluid to the surface of aggregates of animal cells cultured in a rotating bioreactor. These aggregates move through different regions of the bioreactor with a local flow field and concentration distribution that vary with time. The time variation of the Sherwood number and the surface concentration for a range of parameters typical of a cell science experiment executed in the Rotating Wall Perfused Vessel (RWPV) bioreactor in space are investigated. The Reynolds numbers experienced by the aggregate are generally low ( Re < 1) and the Peclet numbers range from O(1) to O(100). Comparison of the results from the numerical solution of the mathematical model with those from a quasi‐steady model, using a steady‐state correlation for mass transport on a sphere, indicate that the quasi‐steady assumption is not a good model to compute the instantaneous Sherwood number. This indicates a significant history effect in the Sherwood number response to the variations of acceleration of the aggregates in the bioreactor. A high resistance to the mass transport from the bulk fluid to the surface of the aggregate exists for the bioreactor operated in micro gravity. The difference between the surface concentration and the free stream concentration was as high as 30% for aggregates larger than 3 mm. Diffusion reduces the variations of the free stream concentration resulting in a nearly constant value for the concentration at the surface of the aggregates. © 2006 Wiley Periodicals, Inc.