(485f) CFD Simulation of the O2 and CO2 Levels in Mammalian Cell Respiration inside an Aerated Stirred Bioreactor

The cell respiration process of a Chinese Hamster Ovary (CHO) cell culture in a large-scale aerated and stirred bioreactor was modeled and simulated by using M-Star’s LES software. The simulation set up was first validated with no cells present. The volume-averaged volumetric mass transfer coefficient ( ) and dissolved O₂ (DO, %) plots are in good agreement with the experimental measurement obtained using the dynamic method. Then, the cells were added to the simulation hypothetically by defining a reaction that couples the O₂ consumption rate to the CO₂ production rates. A controller was set on the pure O₂ sparger to control the DO in the tank. Some simplifying assumptions were made such that only the CO₂ variations as a result of the cell respiration were modeled. The simulation was run for almost one month on GPUs and the dissolved O₂ and CO₂ concentration evolution with time are plotted. The rates of O₂ transfer and consumption rates as well as CO₂ production and absorption rates were simulated successfully to produce results which look qualitatively correct and are in good agreement with the limited validation data available. Finally, the local dissolved CO₂ concentration data were used to calculate local and averaged partial pressure of CO₂ (pCO₂) data in the reactor which remained well in the suggested range. Overall, the simulation approach showed great potential in capturing the local heterogeneities in dissolved O₂ and CO₂ concentrations.