Mathematics reveals new insights into Marangoni flows

The Marangoni effect can have a variety of applications, for example in welding and computer manufacturing. Therefore, Bickel's findings could provide important new information for researchers and engineers working with fluid-based systems. Bickel found that in deeper water, the region in which impurities are swept away decreases in size with an increase in the surface's elasticity. Outside of these regions, Marangoni flows are cancelled out by counterflows originating from the impurities, meaning the fluid becomes static. The region can even disappear if the surface's elasticity is too great, in which case the concentration of impurities on the interface becomes constant. Furthermore, the boundary of the region becomes more blurred in shallow water.

Bickel uncovered these mechanisms through mathematical derivations, starting from the known properties of Marangoni flows. He then incorporated aspects including water depth and impurity concentration, and he calculated their effect on the overall system. Bickel's research shows that even in old, well-studied physics experiments, mathematical analysis can still reveal new processes.