in this paper the dynamic of a droplet on a surface with a hole is investigated under gravitational effect by using lattice boltzmann method. incompressible two-phase flow with high density ratio proposed by lee is considered. cahn’s theory is used to observe the wettability of the surface in contact with liquid and gas phases. several parameters such as contact angle, surface tension and gravi...

Dropwise condensation processes, where condensation occurs through small droplets on a solid surface, has been demonstrated to significantly improve heat transfer rates in comparison to film-wise condensation (where a whole surface is covered by a thin film of liquid). Dropwise condensation usually takes place on superhydrophobic surfaces, and one of the main engineering and scientific challeng...

the aim of the present study was to investigate the influence of nozzle configurations on spray drift and explain the influences using several atomization characteristics (length of spray sheet, spray angle, velocity distribution of flow field, fluctuation of velocity, and droplet size). nozzles manufactured by one company (lechler gmbh, germany) were tested by spraying local tap water in a win...

T he contact angle of a droplet impinging upon a hot surface undergoes changes as the drop spreads and recoils. The motion of the liquid and the effect of evaporation from the edges of the drop affect the contact angle. The changes in the contact angle during spreading affect the spreading characteristics of the droplet upon impact. However, the models available in literature for the maximum sp...

Coating of a surface by droplet spreading plays an important role in many novas industrial processes, such as plasma spray coating, ink jet printing, nano safeguard coatings and nano self-assembling. Data analysis of nano and micro droplet spreading can be widely used to predict and optimize coating processes. In this article, we want to select the most appropriate statistical distribution for ...

Droplet impact dynamics of the shear-thinning fluids on the hydrophobic surfaces have been experimentally studied and compared to the base fluid, water. In this work, hydrogels are prepared by lading water with Polyacrylamide polymer at three loading rates 1, 2, and 3 wt. %. The resultant hydrogel phase behaves as a shear thinning fluid with altered rheophysical properties. The presence of poly...