As the global demand for clean-label, sustainable, and resilient food products rises, biotechnology is reshaping the way we think about food production. Among the key challenges is improving the quality and shelf life of frozen dough products — without chemical additives.
One promising solution is the microbial production of poly-γ-glutamic acid (γ-PGA), a natural polymer that enhances moisture retention and softness. However, scaling up γ-PGA production in bioreactors remains difficult. Bubble formation, stirring-induced mixing, and fluid–structure interaction (FSI) between rotating blades and viscous microbial cultures all affect oxygen delivery — and thus fermentation efficiency.
This project tackles this challenge through advanced numerical simulation. You will develop a finite volume solver on polyhedral meshes to simulate Navier–Stokes flows with immersed moving structures (FSI), and couple it with a conservative level set method to simulate bubble dynamics. Together, these tools will help model realistic bioreactor environments and pave the way for optimizing γ-PGA yields — bringing fluid mechanics into the heart of future food tech.
Objectives of the work (specific tasks will be agreed individually with the student)
• Study the biological background of γ-PGA fermentation and its industrial value.
• Implement FVM for incompressible Navier–Stokes equations with moving boundaries using polyhedral meshes.
• Incorporate fluid–structure interaction (FSI) to simulate rotating blades inside the reactor.
• Develop a conservative level set method to track rising bubbles and gas–liquid interfaces.
• Combine both modules into a coupled solver and validate on simplified test cases.
• Simulate realistic conditions for bubble-aerated stirred reactors and analyze the effect on γ-PGA yield.
Benefits for the student
• Gain experience in advanced CFD, including FSI and multiphase modeling.
• Learn to implement scalable, parallelizable finite volume solvers.
• Work with industrially relevant problems in food and bioprocess engineering.
• Contribute to publications at the frontier of numerical modeling and sustainable production.
Resources
- Liu, H., Yan, Q., Wang, Y., Li, Y., & Jiang, Z. (2025). Efficient production of poly-γ-glutamic acid using computational fluid dynamics simulations by Bacillus velezensis for frozen dough bread making. Food chemistry: X, 25, 102247. https://doi.org/10.1016/j.fochx.2025.102247
- Balcázar-Arciniega, N., Rigola, J., & Oliva, A. (2024). Unstructured Conservative Level-Set (UCLS) method for reactive mass transfer in bubble swarms at high density ratio. Journal of Physics: Conference Series, 2766(1), 012062. https://doi.org/10.1088/1742-6596/2766/1/012062
- Balcázar-Arciniega, N., Antepara, O., Rigola, J., & Oliva, A. (2019). A level-set model for mass transfer in bubbly flows. International Journal of Heat and Mass Transfer, 138, 335–356. https://doi.org/10.1016/j.ijheatmasstransfer.2019.04.008
- Olsson, E., & Kreiss, G. (2005). A conservative level set method for two phase flow. Journal of Computational Physics, 210(1), 225–246. https://doi.org/10.1016/j.jcp.2005.04.007
