Mixing time and kinetic energy measurements in a shaken cylindrical bioreactor

Establishment of a CFD‐based kLa model in microtiter plates to support CHO cell culture scale‐up during clone selection

“…Weheliye et al present an experimental setup with phase resolved PIV and a dual pH indicator system that enables them to investigate the flow pattern in cylindrical well plates. In the presumably same setup, mixing times and flow patterns of a cylindrical microtiter plate were measured by Rodriguez et al They found a transition from laminar to turbulent flow for a Fraude number of Fr do > 0.11. Ducci and Weheliye expand the investigated parameters of the previous setup by testing different viscosities, finding a relation between turbulent structures and the viscosity of the liquid.…”

“…A similar setup to the work by Ducci and collegues was used by Salek et al and combined with CFD for model validation. They found laminar treatment and gravity force combined with a moving mesh method to be accurate in predicting the flow pattern and the free surface.…”

The flow inside shaking flasks and its implication for mycelial cultures

“…Clearly, these two averaging strategies provide slightly different description of the flow. Evidently, when using phase locking (left column), the velocities for a specific instant of the shaking cycle are observed Rodríguez et al, 2013). The time average, in turn, gives a global description of the fluid motion through the entire cycle.…”

“…Discacciati et al (2013) developed a numerical method to study the velocity field and the interface discontinuities to describe the flow behavior in orbitally shaken bioreactors at different agitation rates. Recently, Weheliye et al (2013) and Rodríguez et al (2013) provided a thorough description of the dynamics of the flow occurring inside a cylindrical shaken bioreactor using phase-resolved particle image velocimetry (PIV) as well as the mixing time data obtained with a colorimetric pH technique. Several parameters are used for the hydrodynamic characterization of stirred vessels and shaken flasks, namely: power consumption, mixing times and flow fields.…”

Electromagnetic stirring in a microbioreactor with non‐conventional chamber morphology and implementation of multiplexed mixing

“…Video analysis to determine the mixing time was performed using a modified version of the method used by Rodriguez et al 26 to analyze mixing within shaken cylindrical bioreactors. Due to the differing geometry, optical effects resulting from the inability to illuminate the reactor chamber as effectively as Rodriguez et al 26 were present. Mitigating the greater noise that resulted from the optical effects led to the simple moving average (SMA) of the normalized standard deviation )) were still too high to determine the specific point at which 95% mixing was obtained as per Rodriguez et al 27 Therefore, an automated method of determining the frame at which mixing had started and a semi-automated method of calculating the point at which the SMA of the…”