Analysis of hollow wall effect on the fluid dynamics in the orbitally shaken bioreactors.

Orbitally shaking bioreactors (OSRs) have recently been increasingly applied in the biopharmaceutical industry because they can provide a suitable environment for mammalian cell growth and protein expression. Fluid dynamics information is crucial for analyzing or optimizing of different types of bioreactors. Considering that the structure has an important influence on the fluid dynamics in a bioreactor, it necessary to design or optimize its structure by the computational fluid dynamics (CFD) approach. The aim of this study is to optimize the wall structure of a hollow cylinder OSR proposed in our previous work. Based on previous research, the influences of the hollow wall of the OSR on fluid dynamics and the volumetric mass transfer coefficient ([Formula: see text]) were analysed by the established CFD model. The results showed that the mixing performance of OSR could be improved by decreasing the installation height of the hollow wall. An installation height of 30 mm was found to be most favourable for mixing. The reliability of the CFD model was verified by comparing the liquid wave height and liquid wave shape between the simulation and experiment. The shear stress in the hollow cylinder OSR was proven gentle for mammalian cell cultivation.