Using CFD, the Advent team was able to simulate the fluid dynamics and the working parts of the bioreactor to simulate conditions that would normally be time-intensive or impractical on a manufacturing-scale bioreactor. Leveraging the team’s extensive technical training, credentials, and real-world experience, Advent began by benchmarking a CFD model with one experiment, then testing how changing parameters in the CFD model impacted bioreactor performance. This saved significant time that would otherwise have been spent conducting time and resource consuming experiments.
Because the oxygen transfer rate, kLa, was the primary performance parameter of interest, the Advent team benchmarked a mesh-independent CFD model against an experimentally determined kLa. Advent then changed operating parameters (i.e., impeller speed and the gas sparge rate) on the mesh-independent model and compared the kLa prediction to experimental data. Good agreement provided confidence that the benchmarked bioreactor CFD model could be used to simulate various operating conditions to predict bioreactor performance.
Simulation models enabled the team to evaluate a variety of parameters, including:
- Velocity field for both gas and liquid phase
- Agitator fluid torque
- Fluid volumetric power
- Shear stress
- Overall hold-up
- Overall kLa value and distribution
- Gas phase volume fraction distribution
- Bubble residence time
- Bubble size group distribution
- Mean bubble diameter
By leveraging CFD as a predictive tool, the team delivered insight into different operating conditions and gas sparger designs
