Hanging droplets from liquid surfaces

Liquid droplets on hot surfaces

In this seminar behaviour of liquid droplets on a very hot surface is presented and a simple model is introduced to describe droplet evaporation. Special cases where droplet dynamics is involved are mentioned, important processes and their qualitative description is presented. This seminar supplements a previous seminar Leidenfrost effect, presented in December 2011.

Spreading of thin volatile liquid droplets on uniformly heated surfaces

We develop a mathematical model for the spreading of a thin volatile liquid droplet on a uniformly heated surface. The model accounts for the effects of surface tension, evaporation, thermocapillarity, gravity and disjoining pressure for both perfectly wetting and partially wetting liquids. Previous studies of non-isothermal spreading did not include the effects of disjoining pressure and there...

Sliding droplets on hydrophilic/superhydrophobic patterned surfaces for liquid deposition

Analysis of levitation of saturated liquid droplets on permeable surfaces

Steady-state evaporation of a saturated liquid droplet and its levitation over a solid surface due to momentum-induced pressure in the vapor film is studied by solving the axisymmetric governing equation numerically. A previous on~ime~onal analysis shows that the distance (or gap) between the solid surface and the droplet decreases when the vapor can penetrate the solid. For porous layers, this...

Air entrainment during impact of droplets on liquid surfaces

We study drop impact on a deep pool of the same fluid, with an emphasis on the air layer trapped under the droplets from its formation to its rupture. The penetration velocity of the air layer at a very short time scale prior to its rupture is shown, using an energy argument and experimental verification, to be one-half of the impact velocity. We then deduce the dependence of the rupture positi...