Foam films asymmetric drainage

The theoretical analysis indicated that asymmetric drainage was caused by the hydrodynamic instability being a result of surface tension driven flow. A criterion giving the conditions of the onset of instability that causes asymmetric drainage in foam films was proposed. This analysis showed as well that surface-tension-driven flow was stabilised by surface dilational viscosity, surface diffusivity and especially surface shear viscosity. 

Recently Joye et at. [74] have reported a numerical simulation of instability causing asymmetric drainage in foam films. The results obtained confirmed the rapid increase in drainage rate. 

A related phenomenon to asymmetric drainage in horizontal cylindrical foam films is that of the so-called marginal regeneration. This process occurs in vertical foam films subject to both capillary suction from the Plateau borders and gravity. It is manifest as an apparent turbulent motion on the margin of foam films where thin elements of film are drawn out of the Plateau border and thick elements are sucked... 

It should be clear then that asymmetric drainage of horizontal cylindrical films and marginal regeneration in vertical foam films, although often apparent, are not always exhibited. Liquid flow by capillary suction from the Plateau border is. 

The shape of the gap between two pure liquid drops for different characteristic times is calculated numerically in Refs. 440 and 441. Experimental investigations of these effects for symmetric and asymmetric drainage of foam films were carried out by Joye et al. [442,443]. In some special cases, the deformation of the fluid particle can be very fast For example, the bursting of a small air bubble at an air-water interface is accompanied... 

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