Flows on the Edge: Boundary Interactions and Local Heterogeneities in Complex Fluid Flows

Ever opened a jar of mayonnaise only to find oil separated on top weeks later? It ends up in the trash. What a waste!

Mayonnaise, creams, sauces, and lotions fall under the umbrella of complex fluids that we use every day. They behave like liquids that are easy to scoop or squeeze, yet remain solid enough to hold their shape. They may look simple, but their flow behaviour is surprisingly complex. It depends not only on their internal structure, but also on how these fluids interact with walls of containers, and move through pipes, mixers, or processing vessels. Understanding these microscopic interactions is critical to explain their macroscopic flow behaviour. 

This research combines custom-designed experimental tools and advanced imaging to elucidate how local fluid interactions influence bulk flow. These findings can support industries, from food, and cosmetics to pharmaceuticals, polymers, and paints, to predict and control fluid flow, ultimately ensuring improved product stability, higher processing efficiency and reduced energy consumption.