Hydrodynamic stress in orbitally shaken bioreactors
نویسندگان
چکیده
Materials and methods CHO-DG44 cells were cultivated in suspension in 1-L bottles as described in [1]. To determine conditions under which the shear stress was harmful for the cells, the bottles were orbitally shaken on an ES-X platform (Kühner AG, Birsfelden, Switzerland) at agitation rates from 150 to 200 rpm for 24 h. Control cultures were run in parallel with agitation at 110 rpm. The velocity fields, shear stress, and free surface of a 1-L bottle at 110 rpm were simulated with Computational Fluid Dynamics (CFD). The Navier-Stokes equation was approximated with the finite element method. The simulations were all based on a mesh containing 50’000 tetrahedra and 10’000 vertices. The area of a finite element was 9.8 cm. Because of the chosen discretization, each time step required the resolution of a linear system composed of 190’000 unknowns.
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