Hydrodynamic response of a surfactant-laden interface to a radial flow

Abstract

We study the features of a radial Stokes flow due to a submerged jet directed toward a liquid-air interface. The presence of surface-active impurities confers to the interface an in-plane elasticity that resists the incident flow. Both analytical and numerical calculations show that a minute amount of surfactants is enough to profoundly alter the morphology of the flow. The hydrodynamic response of the interface is affected as well, shifting from slip to no-slip boundary condition as the surface compressibility decreases. We argue that the competition between the divergent outward flow and the elastic response of the interface may actually be used as a practical way to detect and quantify a small amount of impurities.

References in corpus (2)

• Viscous Marangoni propulsion
• Visco-elastic drag forces and crossover from no-slip to slip boundary conditions for flow near air-water interfaces

Cited by in corpus (6)

• Azimuthal instability of the radial thermocapillary flow around a hot bead trapped at the water-air interface
• Surfactant-driven instability of a divergent flow
• Competition between thermocapillary and solutocapillary flows in thin liquid films
• Blockage of thermocapillary flows by surface-active impurities
• Stokes equation in a semi-infinite region: generalization of Lamb solution and applications to Marangoni flows
• Exact solutions for viscous Marangoni spreading