Prediction and simulation on the shear stress and mass transfer in perfused bioreactors I: Circular bioreactors

Bioreactors have been widely used in tissue engineering because of their controllability in environments and operating conditions. But bioreactor design is very complex and still at an early stage of development. Computational fluid dynamics (CFD) is commonly used for the design and manufacture of devices with fluid flow as a powerful computer ldquoexperimentsrdquo modelling and simulation tool. In our work, by the CFD simulations of different circular bioreactors with various parameters, we obtained the concentration status of glucose and lactate in different time and shear stress. It was shown that the inlet or outlet position, and the feed flow rate have quadric relationship with the shear stress. In order to provide the cells with comfortable culture environment, bioreactors should have a lower outlet than inlet, the Hc/Ho should be between 0.2 and 0.4 and the fluid exchange ratio R_fe should be between 0.68 and 6.84 hours.