Elsevier

Chemical Engineering Science

Volume 193, 16 January 2019, Pages 53-65
Chemical Engineering Science

Study of hydrodynamics in wave bioreactors by computational fluid dynamics reveals a resonance phenomenon

https://doi.org/10.1016/j.ces.2018.08.017Get rights and content
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Highlights

  • A resonance phenomenon can occur in Wave bioreactor.

  • This resonance phenomenon can create higher shear stress for lower agitation speed.

  • The fluid hydrodynamics is characterized for 9 operating conditions by CFD.

  • The studied shear stress range can be detrimental for adherent cell cultures.

Abstract

Culture of mammalian or human cells in Wave bioreactor is widely used for cell expansion or for biologics manufacturing. Wave bioreactor cultivation of sensitive cells such as stem cells, immune cells or anchorage-dependent cells, is recognized as an attractive option for culture in suspension or adherently on microcarriers. A systematic optimization of the mixing, oxygen transfer rate and shear stress, most favorable for the cells requires a deep understanding of the hydrodynamics inside the Wave bioreactor bag, i.e. cellbag. Numerical simulation by Computation Fluid Dynamics (CFD), is considered as an inexpensive and efficient tool for predicting the fluid behavior in many fields. In the present study, we perform numerical simulations by Ansys-FLUENT to characterize the flow conditions in a 10 L cellbag. The numerical simulations are carried out to investigate the fluid structures for nine different operating conditions of rocking speed and angle. The influence of these operating parameters on the mixing and the shear stress induced by the liquid motion are studied. We find that the mixing and shear stress increase with the cellbag angle from 4° to 7° but that increasing rocking speeds are not systematically associated with increasing mixing and shear stress. It is concluded that a resonance phenomenon is responsible for the fact that the lowest studied rocking speed, 15 rpm, generates the highest fluid velocity, mixing and shear stress compared to the higher speeds of 22 and 30 rpm.

Keywords

Wave bioreactor
Computation Fluid Dynamics (CFD)
Volume of fluid (VOF)
Hydrodynamic
Resonance

Abbreviations

CFD
Computational Fluid Dynamics
PRESTO!
Pressure Staggering Option
UDF
user-defined functions
VOF
volume of fluid

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