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Orbitally shaken bioreactors—viscosity effects on flow characteristics
Author(s) -
Ducci Andrea,
Weheliye Weheliye Hashi
Publication year - 2014
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.14608
Subject(s) - froude number , turbulence , vortex , mechanics , particle image velocimetry , dissipative system , flow (mathematics) , viscosity , thermodynamics , two phase flow , materials science , physics
Phase‐resolved particle image velocimetry measurements were carried out to assess the flow dynamics occurring in orbitally shaken bioreactors of cylindrical geometry when working fluids of increasing viscosity are considered. Study of the phase‐resolved flow characteristics allowed to built a Re‐Fr map, where four quadrants associated to different flow regimes are identified: in‐phase toroidal vortex (low Fr and high Re), out‐of‐phase precessional vortex (high Fr and high Re), in‐phase single vortex (low Fr and low Re), out‐of‐phase counter‐rotating toroidal vortex (high Fr and low Re). Turbulence levels are found to be significant only in the top right quadrant (high Fr and low Re) and scaling of the turbulent kinetic energy obtained with fluid of varying viscosity is obtained using the ratio of the operating Froude number to the critical Froude number associated to the mean flow transition, F r / F r c . Estimates of the mean flow strain deformation as well as of the flow dissipative scale are provided, while a comparison is made between the flow circulation times obtained for different regimes. © 2014 The Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers AIChE J , 60: 3951–3968, 2014