Surface-Tension-Driven Flows in a Thin Layer of a Water-n-Heptanol Solution.

A model for Marangoni flows that we observed on plane free surfaces of thin layers of aqueous fatty alcohol solutions is developed by considering evaporation-condensation of alcohol. The velocities of surface-tension-driven flows caused by gradients in temperature and in concentration are evaluated for water-n-heptanol solutions, which have a minimum of the equilibrium surface tension near 40 degrees C. Theoretical results are discussed on the basis of experimental observations. Copyright 2001 Academic Press.