Flow Characterization in Wave Bioreactors Using Computational Fluid Dynamics

Quantifying and optimizing the flow conditions in cultivation systems is essential for successful cell growth in major biotechnological applications, like vaccine production processes. Recently, disposable wave bioreactors have been proposed for manufacturing of biologics, leading to markedly different mixing properties compared to stirred tank reactors, i.e. lower shear stress. To describe accurately the conditions in wave bioreactors using numerical simulations, it is first necessary to compute the unsteady flow employing Computational Fluid Dynamics (CFD). Simultaneously, the Volume of Fluid (VOF) method is employed to simulate motion of the free liquid surface. Experimental measurements have been carried out in order to determine liquid surface height, flow velocity and shear stress, which are used as a validation of CFD simulations. The obtained results confirmed low shear stress levels, well below known threshold values leading to cell damage. Recent simulations take additionally into account microcarriers through Population Balance Model (PBM), needed for adherent cell growth.